Heterogeneity in advanced pulmonary sarcomatoid carcinoma and its efficacy to immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with non-small cell lung cancer but rarely been explored in pulmonary sarcomatoid carcinoma (PSC). This multicenter study aimed to evaluate the effectiveness of ICIs for PSC and its underlying mechanism. METHODS: Advanced PSC who received ICIs between August 2018 and May 2022 from 11 centers in China were included. Clinical characteristics and treatment information were collected. Whole-exome sequencing (WES) and whole transcriptome sequencing were conducted on pre-treatment samples to explore the mechanism. RESULTS: 113 patients with PSC were enrolled, the median PFS for patients receiving ICIs therapy was 8.77 months (95 % confidence interval, 4.21 to 13.32). Combining ICIs with anti-angiogenic agents significantly increased PFS (p = 0.04). Liver metastasis and combination therapy with anti-angiogenic agents were independent risk factors for PFS (Hazard Ratio [HR] = 3.652, p = 0.019 and HR = 0.435, p = 0.017, respectively). WES showed that PSC presented with a TMB of 6.3 mutations per million base pairs. High expression of TNFα signaling and glycolysis related gene showed a better prognosis. CONCLUSIONS: ICIs showed promising benefits for advanced PSC, and the addition of anti-angiogenic therapy might be a more effective treatment strategy for this disease.

Endogenous and exogeneous stimuli-triggered reactive oxygen species evoke long-lived carbon monoxide to fight against lung cancer.

Reactive oxygen species (ROS)-associated anticancer approaches usually suffer from two limitations, i.e., insufficient ROS level and short ROS half-life. Nevertheless, no report has synchronously addressed both concerns yet. Herein, a multichannel actions-enabled nanotherapeutic platform using hollow manganese dioxide (H-MnO2) carriers to load chlorin e6 (Ce6) sonosensitizer and CO donor (e.g., Mn2(CO)10) has been constructed to maximumly elevate ROS level and trigger cascade catalysis to produce CO. Therein, intratumoral H2O2 and ultrasound as endogenous and exogeneous triggers stimulate H-MnO2 and Ce6 to produce •OH and 1O2, respectively. The further cascade reaction between ROS and Mn2(CO)10 proceeds to release CO, converting short-lived ROS into long-lived CO. Contributed by them, such a maximumly-elevated ROS accumulation and long-lived CO release successfully suppresses the progression, recurrence and metastasis of lung cancer with a prolonged survival rate. More significantly, proteomic and genomic investigations uncover that the CO-induced activation of AKT signaling pathway, NRF-2 phosphorylation and HMOX-1 overexpression induce mitochondrial dysfunction to boost anti-tumor consequences. Thus, this cascade catalysis strategy can behave as a general means to enrich ROS and trigger CO release against refractory cancers.

A retrospective study of first-line therapy and subsequent pyrotinib treatment in advanced lung adenocarcinoma with HER2 mutations.

OBJECTIVES: HER2 is an infrequently mutated driver gene in non-small cell lung cancer (NSCLC). At present, there has been no comprehensive large-scale clinical study to establish the optimal first-line treatment strategy for advanced lung adenocarcinoma (LUAD) with HER2-Mutant. Besides that, the effectiveness and safety of pyrotinib, a pan-HER inhibitor, in the context of NSCLC are still undergoing investigation. MATERIALS AND METHODS: In this study, we conducted a retrospective data collection of HER2-Mutated advanced LUAD who received first-line treatment and pyrotinib between May 2014 and June 2023. Patients treated with chemotherapy, chemotherapy + immune checkpoint inhibitors (ICIs), chemotherapy + bevacizumab and pyrotinib in first-line treatment. Furthermore, we collected data on the efficacy and safety of pyrotinib in these patients after disease progression. The main endpoint of the study was progression-free survival (PFS). RESULTS: In the final analysis, 89 patients were included in the first-line cohort and 30 patients were included in the pyrotinib cohort. In the first-line treatment cohort, chemotherapy + ICIs, chemotherapy + bevacizumab, and pyrotinib exhibited notable survival benefits compared to chemotherapy (median PFS: 9.87 vs. 7.77 vs. 7.10 vs. 5.40 months, p-value < 0.05). Furthermore, patients with a first-line treatment PFS of less than 6 months may potentially benefit from subsequent treatment with pyrotinib (median PFS: 7.467 vs. 3.000, p-value = 0.0490). CONCLUSIONS: In the first-line treatment of HER2-Mutant LUAD, regimens involving combinations like chemotherapy + ICIs, chemotherapy + bevacizumab, and pyrotinib may confer enhanced survival advantages compared to chemotherapy. Nevertheless, no significant distinctions were observed among these three treatment strategies, underscoring the imperative to identify biomarkers for the discerning selection of suitable therapeutic modalities. Moreover, patients with suboptimal response to first-line treatment may potentially derive more benefit from pyrotinib.

Anti-angiogenic therapy or immunotherapy? A real-world study of patients with advanced non-small cell lung cancer with EGFR/HER2 exon 20 insertion mutations.

Background: For patients with EGFR/HER2 exon20 insertions, platinum-containing double-drug chemotherapy is still the standard treatment method. First-generation TKIs have almost no therapeutic activity against EGFR exon 20 insertions. The efficacy of second-and third-generation TKIs is still controversial. Immunotherapy research is scarce, and there is an urgent need for more evidence and new treatment options for this group of patients. Methods: We reviewed patients with advanced NSCLC with EGFR/HER2 exon 20 insertion mutations treated in Shanghai Chest Hospital and Shanghai Pulmonary Hospital from 2015 to 2022 and assessed the efficacy of receiving chemotherapy, anti-angiogenic therapy and immunotherapy, including objective response rate (ORR) and disease control rate (DCR), and compared progression-free survival (PFS) and overall survival (OS). Results: Of the 126 patients included in the study, 51 patients had EGFR20ins mutations and 7 5 patients had HER2-20ins mutations. In the first-line treatment, bevacizumab + chemotherapy (Beva+Chemo), ICI+chemotherapy (ICI+Chemo), compared with chemotherapy alone (Chemo), ORR: 40% vs 33.3% vs 15% (p=0.0168); DCR: 84% vs 80.9% vs 67.5% (p=0.1817); median PFS: 8.3 vs 7.0 vs 4.6 months (p=0.0032), ICI+Chemo has a trend of benefiting on OS. Stratified analysis showed that compared with chemotherapy, ICI+Chemo was more effective for EGFR20ins mutation with median PFS: 10.3 vs. 6.3m (P=0.013); Beva+Chemo was more effective for HER2-20ins mutation, with a median PFS: 6.6 vs. 4.3m (p=0.030). In the second-line treatment of EGFR20ins mutation, bevacizumab + chemotherapy has a significant advantage in PFS compared with targeted therapy, median PFS:10.8 vs 4.0 months (P=0.016). Conclusion: For patients with EGFR20ins mutation, compared to chemotherapy, ICI+Chemo prolongs PFS, and after chemotherapy progression, bevacizumab combined with chemotherapy seems better than Furmonertinib-based targeted therapy on PFS. For HER2-20ins mutation, Beva+Chemo may be a better choice.

Mechanisms underlying therapeutic resistance of tyrosine kinase inhibitors in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a malignant clonal disease involving hematopoietic stem cells that is characterized by myeloid cell proliferation in bone marrow and peripheral blood, and the presence of the Philadelphia (Ph) chromosome with BCR-ABL fusion gene. Treatment of CML has dramatically improved since the advent of tyrosine kinase inhibitors (TKI). However, there are a small subset of CML patients who develop resistance to TKI. Mutations in the ABL kinase domain (KD) are currently recognized as the leading cause of TKI resistance in CML. In this review, we discuss the concept of resistance and summarize recent advances exploring the mechanisms underlying CML resistance. Overcoming TKI resistance appears to be the most successful approach to reduce the burden of leukemia and enhance cures for CML. Advances in new strategies to combat drug resistance may rapidly change the management of TKI-resistant CML and expand the prospects for available therapies.

Full spectrum flow cytometry-powered comprehensive analysis of PBMC as biomarkers for immunotherapy in NSCLC with EGFR-TKI resistance.

BACKGROUND: Clinical studies suggest that immune checkpoint inhibitor (ICI) monotherapy has limited benefits in non-small cell lung cancer (NSCLC) patients after epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) failure. However, data about efficacy of ICI plus chemotherapy remain controversial, probably attributed to the heterogeneity among such population, and robust efficacy biomarkers are urgent to explore. METHODS: A total of 60 eligible patients who received ICI plus chemotherapy after EGFR-TKI treatment failure were enrolled, 24 of whom peripheral blood mononuclear cell (PBMC) samples were collected at baseline and after 2 cycles of treatment. We have designed a 23-color-antibody panel to detect PBMC by full spectrum flow cytometry. RESULTS: For EGFR-TKI resistant NSCLC patients: 1) ICI plus chemotherapy achieved an objective response rate (ORR) of 21.7% and a median progression-free survival (PFS) of 6.4 months. 2) clinical characteristics associated with worse efficacy included liver metastasis and platelet-to-lymphocyte ratio (PLR) > 200. 3) the proportion of immune cell subset associated with better efficacy was higher baseline effective CD4+T cells (E4). 4) the baseline expression of immune checkpoint proteins (ICPs) on cell subsets associated with better efficacy included: higher expression of CD25 on dendritic cells (DC) and central memory CD8+T cells (CM8), and higher expression of Lymphocyte activation gene 3 (LAG-3) on effective memory CD8+T cells (EM8). 5) the expression of ICPs after 2 cycles of treatment associated with better efficacy included: higher expression of CD25 on CD8+T/EM8 /natural killer (NK) cells. 6) the dynamic changes of ICPs expression associated with worse efficacy included: significantly decrease of T cell immunoglobulin and ITIM domain (TIGIT) expression on regular T cells (Tregs) and decrease of V-domain immunoglobulin suppressor of T cell activation (VISTA) expression on Th1. 7) a prediction model for the efficacy of ICI plus chemotherapy was successfully constructed with a sensitivity of 62.5%, specificity of 100%, and area under curve (AUC) = 0.817. CONCLUSIONS: Some EGFR-TKI-resistant NSCLC patients could indeed benefit from ICI plus chemotherapy, but most patients are primary resistant to immunotherapy. Comprehensive analysis of peripheral immune cells using full spectrum flow cytometry showed that compared to the proportion of cell subsets, the expression type and level of ICPs on immune cells, especially CD25, were significantly correlated with the efficacy of immunotherapy.

Influence of Exosomes on Astrocytes in the Pre-Metastatic Niche of Lung Cancer Brain Metastases.

BACKGROUND: Lung cancer is the most common cause of cancer-related death globally. There are several reasons for this high mortality rate, including metastasis to multiple organs, especially the brain. Exosomes play a pivotal role in tumor metastasis by remodeling the microenvironment of remote target organs and promoting the pre-metastatic niche's formation. Since astrocytes are indispensable for maintaining the homeostasis of brain microenvironment, it's of great interest to explore the influence of lung cancer cell-derived exosomes on astrocytes to further understand the mechanism of lung cancer brain metastasis. RESULTS: Twenty four h after co-culture of H1299 cell-derived exosomes and SVG P12 cells, the viability of astrocytes decreased and the apoptosis increased. The levels of cytokines in the supernatant including GROα/CXCL1, IFN-γ, IL-3, IL-5, IL-15, LIF, M-CSF, NGF, PDGF, and VEGF were significantly enhanced, while IL-7 secretion was significantly reduced. Meanwhile, apoptosis-related proteins MAP2K1, TUBA1C, RELA, and CASP6 were up-regulated. And the differentially expressed proteins were involved in regulating metabolic pathways. CONCLUSION: Exosomes of H1299 could induce apoptosis of astrocytes as well as promote their secretion of cytokines that were conducive to the formation of the inflammatory microenvironment and immunosuppressive microenvironment, and affect their metabolic pathways, thus facilitating the formation of pre-metastatic niche in lung cancer brain metastases.

Hepatic mitochondrial NAD + transporter SLC25A47 activates AMPKα mediating lipid metabolism and tumorigenesis.

BACKGROUND AIMS: SLC25A47 was initially identified as a mitochondrial HCC-downregulated carrier protein, but its physiological functions and transport substrates are unknown. We aimed to investigate the physiological role of SLC25A47 in hepatic metabolism. APPROACH RESULTS: In the treatment of hepatocytes with metformin, we found that metformin can transcriptionally activate the expression of Slc25a47 , which is required for AMP-activated protein kinase α (AMPKα) phosphorylation. Slc25a47 -deficient mice had increased hepatic lipid content, triglycerides, and cholesterol levels, and we found that Slc25a47 deficiency suppressed AMPKα phosphorylation and led to an increased accumulation of nuclear SREBPs, with elevated fatty acid and cholesterol biosynthetic activities. Conversely, when Slc25a47 was overexpressed in mouse liver, AMPKα was activated and resulted in the inhibition of lipogenesis. Moreover, using a diethylnitrosamine-induced mouse HCC model, we found that the deletion of Slc25a47 promoted HCC tumorigenesis and development through the activated mammalian target of rapamycin cascade. Employing homology modeling of SLC25A47 and virtual screening of the human metabolome database, we demonstrated that NAD + was an endogenous substrate for SLC25A47, and the activity of NAD + -dependent sirtuin 3 declined in Slc25a47 -deficient mice, followed by inactivation of AMPKα. CONCLUSIONS: Our findings reveal that SLC25A47, a hepatocyte-specific mitochondrial NAD + transporter, is one of the pharmacological targets of metformin and regulates lipid homeostasis through AMPKα, and may serve as a potential drug target for treating NAFLD and HCC.

Special issue "The advance of solid tumor research in China": Real-world clinical outcomes of alectinib for advanced nonsmall-cell lung cancer patients with ALK fusion in China.

Global phase 3 trials have demonstrated the priority of several next-generation anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs). However, clinical studies are conducted with specific populations that differ from the real world. The study aimed to evaluate the clinical outcomes of alectinib in real-world settings. Patients with advanced nonsmall-cell lung cancer (NSCLC) and EML4-ALK fusion were enrolled from two medical centers between June 2018 and June 2020. The primary endpoints were objective response rate (ORR) and progression-free survival (PFS) to alectinib. The secondary endpoint was response of brain metastases. The risk factors for disease progression were also investigated. In total, 127 patients with advanced NSCLC were enrolled into this study. Of them, 54.3% received first-line alectinib. The 1- and 2-year PFS rates were 77.4% and 68.3%, respectively. ORR and disease control rate (DCR) were 53.5% and 91.3%, respectively. Among patients with brain metastases, intracranial ORR and DCR were 63.6% and 88.6%, respectively. In addition, we found that "crizotinib pretreatment", "liver metastasis" and "TP53 co-mutation" were individually associated with shorter PFS in alectinib treatment. In conclusion, this study confirms the salient clinical outcomes of alectinib for ALK-fusion-driven NSCLC patients with or without brain metastases, adding real-world evidence to the priority of alectinib in clinical practice.

The clinical outcome and risk factors analysis of immune checkpoint inhibitor-based treatment in lung adenocarcinoma patients with brain metastases.

Background: The data about efficacy of immunotherapy for non-small cell lung cancer with brain metastases (BMs) from real-word settings are controversial. This real-word study is aimed to evaluate the clinical outcome of immune checkpoint inhibitor (ICI)-based treatment in lung adenocarcinoma patients with brain metastases (BMs) and explore potential risk factors, with a focus on the spatial distribution of BMs as previous studies suggested spatial heterogeneity on the brain immune microenvironment. Methods: Advanced lung adenocarcinoma patients with non-oncogene-addicted, who received ICI monotherapy or plus chemotherapy, were enrolled. Efficacy was assessed by Response Evaluation Criteria in Solid Tumors version 1.1. Intergroup comparisons were performed using Pearson's χ2 or Fisher's exact tests for categorical variables. The progression-free survival (PFS) was estimated using Kaplan-Meier method and compared using log-rank test. Cox proportional hazards model was used for multivariate analyses. Peripheral blood was collected from 15 patients with BMs. Tumor-derived exosomes in plasma were isolated by size exclusion chromatography and the cDNA library preparations for miRNA were sequenced on an Illumina Hiseq platform. Differentially expressed genes in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed. Results: A total of 198 patients were enrolled and brain metastasis occurred in 20.7% patients (N=41). Compared with patients without BMs, those with BMs had a comparable objective response rate (ORR; 29.3% vs. 43.9%; P=0.089), a lower disease control rate (DCR; 58.5% vs. 78.3%; P=0.01), and a shorter PFS (3.6 vs. 8.6 months; P=0.069). For patients with BMs, factors, including the presence of neurological symptoms, the treatment of intracranial radiotherapy, and the combination of ICI with chemotherapy, had no impact on PFS, whereas cerebellum metastasis was significantly associated with shorter PFS (2.8 vs. 13.8 months, P=0.007). Six upregulated miRNAs were identified in patients with cerebellum metastases (N=8) compared with those without (N=7). The enrichment of differentially expression genes in the KEGG pathways indicated upregulated sulfur metabolism pathway in patients with cerebellum metastases. Conclusions: For lung adenocarcinoma patients, those with BMs have inferior response to ICI-based treatment, but not significantly, and cerebellum metastasis is an independent risk factor with poor outcome for such patients, might attributing to the upregulated sulfur metabolism.

Microenvironment and the progress of immunotherapy in clinical practice of NSCLC brain metastasis.

One of the most frequent distant metastases of lung cancer occurs in the brain. The average natural survival duration for patients with lung cancer who have brain metastases is about 1 to 2 months. Knowledge about brain metastases is currently restricted since they are more difficult to acquire than other metastases. This review begins with an analysis of the immune microenvironment of brain metastases; focuses primarily on the functions of microglia, astrocytes, neurons, and tumor-infiltrating lymphocytes in the microenvironment of brain metastases; and offers an atlas of the immune microenvironment of brain metastases involving significant cells. In an effort to give researchers new research ideas, the study also briefly covers how immunotherapy for non-small cell lung cancer with brain metastases is currently faring.

Treatment efficacy of HER2-mutant lung adenocarcinoma by immune checkpoint inhibitors: a multicenter retrospective study.

BACKGROUND: Despite the remarkable clinical advance of immune checkpoint inhibitors (ICIs) in the treatment of lung cancer, there are limited studies focused on evaluating efficacy of ICIs for patients with human epidermal growth factor receptor 2 (HER2)-mutant lung adenocarcinoma. METHODS: We conducted a multicenter retrospective study of patients with HER2-mutant lung adenocarcinoma who received ICIs therapy at Shanghai Pulmonary Hospital, Shanghai Chest Hospital and the First Affiliated Hospital of Wenzhou Medical University between 2016 and 2021. Response was defined with reference to the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. RESULTS: Among the 26 patients enrolled in our study, the overall objective response rate (ORR) was 38.5%, disease control rate (DCR) was 84.6% and median progression-free survival (PFS) was 7.4 months. Majority of patients were treated with immunochemotherapy combination regimens (16/26, 61.5%), with a median PFS of 8.4 months. Among the 9 patients receiving ICIs-based therapy as first-line treatment, 5 patients had partial response (PR) and 4 patients had stable disease (SD), with a median PFS of 9.1 months. Of the entire cohort, 5 patients who received ICIs before epidermal growth factor receptor (EGFR)/HER2-targeting drugs achieved a median PFS of 8.4 months. CONCLUSION: Our retrospective study provides clinical evidence that front line of ICIs-based therapy is also worth considering for the treatment to improve survival outcomes of patients with HER2-mutant lung adenocarcinoma.

Low baseline plasma PCSK9 level is associated with good clinical outcomes of immune checkpoint inhibitors in advanced non-small cell lung cancer.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a crucial protein involved in the metabolism of low-density lipoprotein cholesterol. However, the role of plasma PCSK9 in predicting the efficacy of ICIs in advanced non-small cell lung cancer (NSCLC) remains to be clarified. METHODS: We retrospectively reviewed the medical records of NSCLC patients who presented at Shanghai Pulmonary Hospital between April 2019 and June 2020. ELISA was conducted to detect the concentration of PCSK9. Clinical efficacy was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1). RESULTS: A total of 55 patients were enrolled in the study. The median progression-free survival (PFS) following treatment with ICIs in all patients was 9.9 months. The optimal threshold of baseline plasma PCSK9 was 232.2 ng/ml. Patients with low baseline plasma PCSK9 had a longer PFS (NR vs. 7.37 months, p = 0.017, HR = 0.207, 95% CI: 0.086-0.498) and a better response (ORR 71.4% vs. 43.9%, p = 0.075, DCR 100% vs. 80.5%, p = 0.098) to ICIs. Younger patients (≤66 years) with a lower PCSK9 had a significantly longer PFS and higher treatment response than those with a high baseline level of PCSK9 (NR vs. 5.83 months, p = 0.021, HR = 0.134, 95% CI: 0.044-0.409; ORR 66.7% vs. 30.0%, p = 0.106, DCR 100% vs. 75%, p = 0.153). The situation was similar in patients who received first-line therapy (NR vs. 8.97 months, p = 0.022, HR = 0.138, 95% CI: 0.047-0.400; ORR 63.6% vs. 46.4%, p = 0.480, DCR 100% vs. 89.3%, p = 0.545). Multivariate analysis showed that low PCSK9 concentration was independently associated with PFS (p = 0.032, HR = 0.201). CONCLUSIONS: Low baseline plasma PCSK9 level may predict good outcomes in patients with advanced NSCLC treated with ICIs.

Real-world outcomes of chemo-antiangiogenesis versus chemo-immunotherapy combinations in EGFR-mutant advanced non-small cell lung cancer patients after failure of EGFR-TKI therapy.

BACKGROUND: Despite the potent efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in the treatment of EGFR-mutant non-small cell lung cancer (NSCLC) patients, drug resistance inevitably ensues, and there remains a paucity of treatment options in clinical practice. METHODS: We identified patients with EGFR-mutant advanced NSCLC presenting to Shanghai Pulmonary Hospital and Shanghai Chest Hospital between January 2015 and December 2020 treated with chemo-antiangiogenesis or chemo-immunotherapy combinations after EGFR-TKI resistance. Patient information was collected, and the objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS) were assessed. RESULTS: A total of 144 patients who met our inclusion criteria were enrolled. Chemo-immunotherapy combinations achieved a higher objective response rate (ORR) compared with chemo-antiangiogenesis combinations (29.5% vs. 13.0%, P=0.018). The DCR was similar between the two groups (93.0% vs. 88.6%, P=0.585), as was the median PFS (7.59 vs. 6.90 months, P=0.552). In the subgroup analyses, patients who developed secondary T790M mutations after EGFR-TKI treatment were less likely to benefit from chemo-immunotherapy combinations than their T790M-negative counterparts (3.42 vs. 7.63 months, P=0.028). For patients who received chemo-antiangiogenesis combinations after TKI resistance, no significant difference was observed in the median PFS between T790M-positive and T790M-negative patients (median PFS: 5.33 vs. 7.46 months, P=0.202). Additionally, multivariate analysis showed that an elevated platelet count was independently associated with a worse PFS for both groups. CONCLUSIONS: The efficacy of chemo-immunotherapy combinations was comparable to chemo-antiangiogenesis combinations after failure of EGFR-TKI therapy. For patients harboring EGFR T790M mutations, chemo-antiangiogenesis combinations may be the preferred therapeutic option. In addition, platelet count could be a potential prognostic factor for patients after failure of EGFR-TKI therapy. Further research should be conducted on larger populations and in a prospective setting.

Cascade Lactonization/Benzannulation of Propargylamines with Dimethyl 3-Oxoglutarate for Modular Assembly of Hydroxylated/Arene-Functionalized Benzo[c]chromen-6-ones.

A DBU-mediated cascade strategy of propargylamines with dimethyl 3-oxoglutarate for constructing a functionalized benzo[c]chromen-6-one core has been achieved. This cascade process presumably involves a sequence of 1,4-conjugate addition, followed by lactonization, alkyne-allene isomerization, enol-keto tautomerization, 6π-electrocyclization, and aromatization. This protocol features mild reaction conditions, simple operation, rich structural diversity, and good functional group tolerance. A photophysical survey reveals that the benzo[c]chromen-6-one products exhibit fluorescence properties and show potential for exploring fluorescent material applications.

Rh(III)-Catalyzed Cascade Nucleophilic Addition/Annulation of 2-Diazo-1,3-diketones with 1,3-Dicarbonyl Compounds To Access 6,7-Dihydrobenzofuran-4(5H)-ones.

A Rh(III)-catalyzed cascade nucleophilic addition/intramolecular annulation of 2-diazo-1,3-diketones with 1,3-dicarbonyl compounds (e.g., 1,3-diketones and ß-keto esters) is achieved to afford 6,7-dihydrobenzofuran-4(5H)-ones in up to 91% yields. Notably, a wide range of substrates and functional groups were well-tolerated under the optimized reaction conditions to give desired products in moderate to excellent yields with release of N2 and H2O as byproducts. Moreover, the method described is scalable and adaptable to late-stage functionalization.

A cascade double 1,4-addition/intramolecular annulation strategy for expeditious assembly of unsymmetrical dibenzofurans.

Existing synthetic routes for accessing dibenzofuran core have intrinsic regioselectivity, limiting the substitution patterns available in heteropolycyclic arene products. Here we report a double 1,4-conjugate addition/intramolecular annulation cascade reaction between propargylamines and two equivalents of imidazolium methylides that allows efficient access of structurally versatile dibenzofurans. This transition metal-free protocol proceeds smoothly under bench-top air atmosphere and offers easy manipulation of substituents on the dibenzofuran core, and also provides good-to-excellent product yields with good functional group tolerance, particularly the -Br and -Cl groups which are often incompatible with existing metal-catalyzed C-C and/or C-O bond ring-forming processes. It is worth noting that ladder-type π-systems with all-arene quarternary carbon structure can be straightforwardly generated upon simple late-stage functionalization.

Synthesis of unsymmetrical urea derivatives via one-pot sequential three-component reactions of cyclic 2-diazo-1,3-diketones, carbodiimides, and 1,2-dihaloethanes.

A novel and efficient multicomponent reaction of cyclic 2-diazo-1,3-diketones, carbodiimides, and 1,2-dihaloethanes has been developed, and it leads to unsymmetrical urea derivatives with good yields in a single operation. This transformation involves the cascade formation of C-X (X = Cl, Br, I), C-N and C[double bond, length as m-dash]O bonds through halogenation, nucleophilic addition, ring-opening, and enol-ketone tautomerization processes. This protocol is step- and atom-economical; 1,2-dihaloethane was used as an easily available halogenated reagent, and it is amenable to different functional groups.

Organocatalytic Approach for Assembling Flavanones via a Cascade 1,4-Conjugate Addition/oxa-Michael Addition between Propargylamines with Water.

A DBU-catalyzed one-pot cascade reaction of propargylamines and water for the synthesis of flavanones has been developed. This process proceeds via a sequence of 1,4-conjugate addition of water to alkynyl o-quinone methide (o-AQM), followed by the alkyne-allene isomerization and subsequent intramolecular oxa-Michael addition. This strategy provides a convenient method for accessing a broad range of flavanones in good to excellent yields with good functional-group tolerance, in particular, the reactive halo functional groups.

Rh-Catalyzed C-H activation/intramolecular condensation for the construction of benzo[f]pyrazolo[1,5-a][1,3]diazepines.

A novel and mild Rh(iii)-catalyzed C-H activation/intramolecular condensation of 1-aryl-1H-pyrazol-5-amines with cyclic 2-diazo-1,3-diketones was developed, giving access to various important benzo[f]pyrazolo[1,5-a][1,3]diazepine scaffolds through sequential C-C/C-N bond formation in a one-pot procedure under additive- and oxidant-free conditions. Furthermore, 3-([1,1'-biphenyl]-2-ylamino)-2-ethoxycyclohex-2-enones can be obtained in good yields by constructing C-O and C-N bonds through 1,1'-insertion, dehydration, and isomerization processes.