Chalcone-Based Synthesis of Tetrahydropyridazines via Cloke-Wilson-Type Rearrangement-Involved Tandem Reaction between Cyclopropyl Ketones and Hydrazines.

A facile and efficient approach for the synthesis of multisubstituted tetrahydropyridazines starting from cyclopropyl ketones and hydrazines has been developed. The transformation is chalcone-based and takes place via a Cloke-Wilson-type rearrangement-involved tandem reaction catalyzed by TfOH in HFIP.

Target Profiling of an Iridium(III)-Based Immunogenic Cell Death Inducer Unveils the Engagement of Unfolded Protein Response Regulator BiP.

Clinical chemotherapeutic drugs have occasionally been observed to induce antitumor immune responses beyond the direct cytotoxicity. Such effects are coined as immunogenic cell death (ICD), representing a "second hit" from the host immune system to tumor cells. Although chemo-immunotherapy is highly promising, ICD inducers remain sparse with vague drug-target mechanisms. Here, we report an endoplasmic reticulum stress-inducing cyclometalated Ir(III)-bisNHC complex (1a) as a new ICD inducer, and based on this compound, a clickable photoaffinity probe was designed for target identification, which unveiled the engagement of the master regulator protein BiP (binding immunoglobulin protein)/GRP78 of the unfolded protein response pathway. This has been confirmed by a series of cellular and biochemical studies including fluorescence microscopy, cellular thermal shift assay, enzymatic assays, and so forth, showing the capability of 1a for BiP destabilization. Notably, besides 1a, the previously reported ICD inducers including KP1339, mitoxantrone, and oxaliplatin were also found to engage BiP interaction, suggesting the important role of BiP in eliciting anticancer immunity. We believe that the ICD-related target information in this work will help to understand the mode of action of ICD that is beneficial to designing new ICD agents with high specificity and improved efficacy.

Construction of α,ß-Diamino Diacid Derivatives with Adjacent Acyclic Tetrasubstituted Stereocenters.

A convenient strategy for the diastereoselective synthesis of α,ß-diamino diacid derivatives bearing congested vicinal acyclic tetrasubstituted stereocenters via catalytic Mannich-type reactions of azlactones and 2-aminoacrylates was established. A diverse set of α,ß-diamino diacid derivatives were synthesized in good to excellent yields and diastereoselectivities. Good enantioselectivity (up to 98:2 er) was achieved by employing the catalyst (DHQD)2PHAL in the subsequent asymmetric study.

Synthesis of Phenolic Coumestans via a Sequential Dehydrogenation/Oxa-Michael Addition Reaction of 2',4'-Dihydroxyl-3-arylcoumarins.

A facile and practical approach for the synthesis of natural coumestans and derivatives starting from 2',4'-dihydroxyl-3-arylcoumarins has been developed. The process involved a seqential intramolecular dehydrogenation/oxa-Micheal reaction efficiently promoted by 1,8-diazabicyclo[5.4.0]undec-7-ene at 40 °C under metal- and ligand-free conditions with good functional group compatibility.

Discovery of a potent EGFR and ALK dual mutation inhibitor containing N-(3-((4-((2-(cyclopropylsulfinyl)phenyl)amino)pyrimidin-2-yl)amino) phenyl)acrylamide scaffold.

A series of EGFR and ALK dual inhibitors containing sulfoxide and cyclopropyl groups were designed and synthesized. The lead compound 8a showed a significant activity against EGFR and ALK in both the enzymatic and cellular assays. The study of anti-tumor mechanism indicated that 8a could effectively block the phosphorylation of EGFR and ALK proteins, so as to effectively inhibiting the proliferation and inducing apoptosis of H1975 tumor cells, blocking the cell cycle and reducing the mitochondrial membrane potential inhibited the migration of H1975 cells. In vivo studies, compounds 8a and 8d can significantly subside the tumor tissue of nude mice without obvious toxicity.

Stereoselective Synthesis of Trisubstituted Alkenes by Nickel-Catalyzed Benzylation and Alkene Isomerization.

Catalytic strategies that provide stereoselective access to highly substituted alkenes from abundant monosubstituted substrates are exceedingly sought-after but rare. Here, we show that a N-heterocyclic carbene-NiI catalytic species mediates efficient union of electronically polarized terminal olefins with benzyl chlorides, in the presence of trimethylsilyl triflate and trimethylamine additives, to generate trisubstituted boron- and arene-containing trans alkenes in excellent regio- and stereoselectivities. Control experiments provide evidence for a mechanism involving branched-selective Heck-type benzylation that overrides substrate control, followed by trans-selective 1,3-hydrogen shift. The method represents a significant addition to the toolbox of reactions for the concise synthesis of unsaturated biologically active compounds.

Organocatalytic Asymmetric Synthesis of Benzothiazolopyrimidines via [4 + 2] Cyclization of 2-Benzothiazolimines and Aldehydes.

We report the direct asymmetric synthesis of pyrimido[2,1-b]benzothiazoles using a commercially available chiral amine catalyst. A variety of 2-benzothiazolimines and aldehydes were well tolerated under the reaction conditions and generated the corresponding products in 81-99% yields with excellent diastereoselectivities and enantioselectivities (up to >20:1 dr, 99% ee). Furthermore, the products could be easily converted to other useful chiral building blocks.

Aromatic C-H Methylation and Other Functionalizations via the Rh(III)-Catalyzed Migratory Insertion of Bis(phenylsulfonyl)carbene and Subsequent Transformations.

The Rh(III)-catalyzed migratory insertion of bis(phenylsulfonyl)carbene into aromatic C-H bonds has been developed. A variety of bis(phenylsulfonyl)methyl derivatives were prepared with good yields under mild conditions. The methylated products were readily obtained after reductive desulfonylation. Furthermore, the diverse transformations of bis(phenylsulfonyl)methyl to trideuteriomethyl, aldehyde, and other functional groups were demonstrated.

Copper-Catalyzed Lactamization of (E)-2-(2-Bromophenyl)-3-arylacrylamides for the Synthesis of (E)-3-Arylideneindolin-2-ones.

A copper-catalyzed, ligand-free intramolecular C-N coupling of (E)-2-(2-bromophenyl)-3-arylacrylamides has been developed. This protocol provides an efficient and practical synthetic route for the biologically important (E)-3-arylideneindolin-2-ones from o-bromophenylacetic acids and aromatic or conjugated alkenyl aldehydes. Readily available starting materials, mild and noble metal-free conditions, high efficiency, and good tolerability for phenolic hydroxyl groups make this approach attractive and applicable.

Synthesis and evaluation of novel 2,4-diaminopyrimidines bearing a sulfoxide moiety as anaplastic lymphoma kinase (ALK) inhibition agents.

Anaplastic lymphoma kinase (ALK) targeted therapies have demonstrated remarkable efficacy in ALK-positive lung adenocarcinomas. Here we synthesized and evaluated sixteen new 2,4-diaminopyrimidines bearing a sulfoxide moiety as anaplastic lymphoma kinase (ALK) inhibitors. The optimal compound 9e exhibited excellent antiproliferative activity against non-small cell lung cancer NCI-H2228 cells, which is better than that of Brigatinib and similar to Ceritinib. Mechanism study revealed that the optimal compound 9e decreased the mitochondrial membrane potential and arrested NCI-H2228 cells in the G0/G1 phase, finally resulting in cellular apoptosis. It is interesting that 9e could effectively inhibit the migration of NCI-H2228 cells and may be a promising leading compound for chemotherapy of metastatic cancer.

Bioorthogonal Activation of Dual Catalytic and Anti-Cancer Activities of Organogold(I) Complexes in Living Systems.

Controllably activating the bio-reactivity of metal complexes in living systems is challenging but highly desirable because it can minimize off-target bindings and improve spatiotemporal specificity. Herein, we report a new bioorthogonal activation approach by employing Pd(II)-triggered transmetallation reactions to conditionally activate the bio-reactivity of NHC-Au(I)-phenylacetylide complexes (1 a) in vitro and in vivo. A combination of 1 H NMR, LC-MS, DFT calculation and fluorescence screening assays reveals that 1 a displays a reasonable stability against biological thiols, but its phenylacetylide ligand can be efficiently transferred to Pd(II), leading to in situ formation of labile NHC-Au(I) species that is catalytically active inside living cells and zebrafish, and can meanwhile effectively suppress the activity of thioredoxin reductase, potently inhibit the proliferation of cancer cells and efficiently suppress angiogenesis in zebrafish models.

Asymmetric Synthesis of Oxindole-Derived Vicinal Tetrasubstituted Acyclic Amino Acid Derivatives by the Mannich-Type Reaction.

The catalytic asymmetric Mannich-type reaction of 3-hydroxy/3-aminooxindoles with 2-aminoacrylates to afford oxindole-derived acyclic amino acid derivatives bearing vicinal tetrasubstituted stereocenters is reported. (DHQ)2PHAL (4g) and quinine-derived squaramide (4d) were identified as efficient catalysts. Transformations of the Mannich-type reaction products highlight the utility of this synthetic strategy.

Divergent syntheses of okaramines C, J, L, and S-U.

The total synthesis of six novel okaramines (C, J, L, and S-U) was accomplished with a precise synthesis scheme involving a few steps and a practical yield of 6.7%-23% was obtained. The significance of this study includes the design of a successful and convenient synthesis method for preparation of 3a-hydroxy-pyrrolo[2,3-b]-indole and C-7 prenylated l-tryptophan derivatives using a nucleophilic attack of cyclopropylazetoindoline and an aza-Claisen rearrangement of N-reverse-prenyl tryptophan, respectively.

Visible-light-promoted radical cross-coupling of para-quinone methides with N-substituted anilines: an efficient approach to 2,2-diarylethylamines.

An efficient protocol to access 2,2-diarylethylamines via visible-light-promoted radical reactions of para-quinone methides (p-QMs) with N-alkyl anilines has been disclosed. These reactions feature metal-free, redox-neutral, and mild reaction conditions with wide functional group compatibility.

Use Characteristics and Triage Acuity of a Digital Symptom Checker in a Large Integrated Health System: Population-Based Descriptive Study.

BACKGROUND: Pressure on the US health care system has been increasing due to a combination of aging populations, rising health care expenditures, and most recently, the COVID-19 pandemic. Responses to this pressure are hindered in part by reliance on a limited supply of highly trained health care professionals, creating a need for scalable technological solutions. Digital symptom checkers are artificial intelligence-supported software tools that use a conversational "chatbot" format to support rapid diagnosis and consistent triage. The COVID-19 pandemic has brought new attention to these tools due to the need to avoid face-to-face contact and preserve urgent care capacity. However, evidence-based deployment of these chatbots requires an understanding of user demographics and associated triage recommendations generated by a large general population. OBJECTIVE: In this study, we evaluate the user demographics and levels of triage acuity provided by a symptom checker chatbot deployed in partnership with a large integrated health system in the United States. METHODS: This population-based descriptive study included all web-based symptom assessments completed on the website and patient portal of the Sutter Health system (24 hospitals in Northern California) from April 24, 2019, to February 1, 2020. User demographics were compared to relevant US Census population data. RESULTS: A total of 26,646 symptom assessments were completed during the study period. Most assessments (17,816/26,646, 66.9%) were completed by female users. The mean user age was 34.3 years (SD 14.4 years), compared to a median age of 37.3 years of the general population. The most common initial symptom was abdominal pain (2060/26,646, 7.7%). A substantial number of assessments (12,357/26,646, 46.4%) were completed outside of typical physician office hours. Most users were advised to seek medical care on the same day (7299/26,646, 27.4%) or within 2-3 days (6301/26,646, 23.6%). Over a quarter of the assessments indicated a high degree of urgency (7723/26,646, 29.0%). CONCLUSIONS: Users of the symptom checker chatbot were broadly representative of our patient population, although they skewed toward younger and female users. The triage recommendations were comparable to those of nurse-staffed telephone triage lines. Although the emergence of COVID-19 has increased the interest in remote medical assessment tools, it is important to take an evidence-based approach to their deployment.

Patient-Centric Scheduling With the Implementation of Health Information Technology to Improve the Patient Experience and Access to Care: Retrospective Case-Control Analysis.

BACKGROUND: Cancellations and rescheduling of doctor's appointments are common. An automated rescheduling system has the potential to facilitate the rescheduling process so that newly opened slots are promptly filled by patients who need and can take the slot. Building on an existing online patient portal, a large health care system adopted an automated rescheduling system, Fast Pass, that sends out an earlier appointment offer to patients via email or SMS text messaging and allows patients to reschedule their appointment through the online portal. OBJECTIVE: We examined the uptake of Fast Pass at its early stage of implementation. We assessed program features and patient and visit characteristics associated with higher levels of Fast Pass utilization and the association between Fast Pass use and no-show and cancellation rates. METHODS: This study was a retrospective analysis of Fast Pass offers sent between July and December 2018. Multivariable logistic regression was used to assess the independent contribution of program, patient, and visit characteristics on the likelihood of accepting an offer. We then assessed the appointment outcome (completion, cancellation, or no-show) of Fast Pass offered appointments compared to appointments with the same patient and visit characteristics, but without an offer. RESULTS: Of 177,311 Fast Pass offers sent, 14,717 (8.3%) were accepted. Overall, there was a 1.3 percentage point (38%) reduction in no-show rates among Fast Pass accepted appointments compared to other appointments with matching characteristics (P<.001). The offers were more likely to be accepted if they were sent in the evening (versus early morning), the first (versus repeated) offer for the same appointment, for a slot 1-31 days ahead (versus same-day), for later in a day (versus before 10am), for a primary care (versus specialty) visit, sent via SMS text messaging (versus email only), for an appointment made through the online patient portal (versus via phone call or in-person), or for younger adults aged 18-49 years (versus those aged 65 years or older; all at P<.001). Factors negatively associated with offer acceptance were a higher number of comorbidities (P=.02) and visits scheduled for chronic conditions (versus acute conditions only; P=.002). CONCLUSIONS: An automated rescheduling system can improve patients' access by reducing wait times for an appointment, with an added benefit of reducing no-shows by serving as a reminder of an upcoming appointment. Future modifications, such as increasing the adoption of SMS text messaging offers and targeting older adults or patients with complex conditions, may make the system more patient-centered and help promote wider utilization.

Cyclometalated Gold(III)-Hydride Complexes Exhibit Visible Light-Induced Thiol Reactivity and Act as Potent Photo-Activated Anti-Cancer Agents.

The specific gold-sulfur binding interaction renders gold complexes as promising anti-cancer agents that can potentially overcome cisplatin resistance; while their unbiased binding towards non-tumoral off-target thiol-proteins has posed a big hurdle to clinical application. Herein we report that cyclometalated gold(III) complexes bearing hydride ligands are highly stable towards thiols in the dark but can efficiently dissociate the auxiliary hydride moiety and generate a gold-thiol adduct when excited with visible light. In consequence, the photo-activated gold(III) complexes potently inhibited thioredoxin reductase in association with up to >400-fold increment of photocytotoxicity (vs. dark condition) without deactivation by serum albumin and along with strong anti-angiogenesis activity in zebrafish embryos. Importantly, the gold(III)-hydride complexes could be activated by two-photon laser irradiation at the phototherapeutic window as effectively as blue-light irradiation.

Synthesis of Javanicunines A and B, 9-Deoxy-PF1233s A and B, and Absolute Configuration Establishment of Javanicunine B.

Javanicunines A-B and 9-deoxy-PF1233s A-B belong to a family of natural diketomorpholines with a unique isopropenyl group at C-10b or C-5a and a hydroxyl group at C-11a or C-10b. We herein reported the first total synthesis of javanicunines A-B and 9-deoxy-PF1233s A-B. Pivotal features of the synthesis included a nucleophilic substitution reaction, followed by a Davis' oxaziridine oxidation to assemble javanicunines A-B, and a chemoselective and stereoselective oxidation with Murray's reagent to install the requisite C-10b hydroxyl group in 9-deoxy-PF1233s A-B. The present synthesis also established the absolute configuration of javanicunine B.

Synthesis of multisubstituted arylsulfones via a one-pot, three-component [3 + 3] benzannulation reaction.

A one-pot, three-component [3 + 3] benzannulation reaction of α,ß-unsaturated carbonyl compounds, bromoallylic sulfones, and sodium sulfinates had been developed. A series of multisubstituted arylsulfones were prepared with moderate to good yields. This method has the advantages of good step-economy, broad substrate scope and operational simplicity.

The design, synthesis and evaluation of selenium-containing 4-anilinoquinazoline hybrids as anticancer agents and a study of their mechanism.

Inhibition of tubulin polymerization is one of the significant strategies in the treatment of cancer. Inspired by the excellent antitumor activity of EP128495 and the beneficial biological activities of selenium compounds, a series of new selenium-containing 4-anilinoquinazoline hybrids were synthesized and evaluated as tubulin polymerization inhibitors. An anti-proliferative activity assay showed that most of the compounds inhibited human sensitive cancer cells at low nanomolar concentrations. A mechanism study revealed that the optimal compound 5a disrupted microtubule dynamics, decreased the mitochondrial membrane potential and arrested HeLa cells in the G2/M phase, finally resulting in cellular apoptosis.