Asymmetric Synthesis of Chiral Calix[4]arenes with Both Inherent and Axial Chirality via Cobalt-Catalyzed Enantioselective Intermolecular C-H Annulation.

Inherently chiral calixarenes have garnered significant attention due to their distinctive properties, yet the development of efficient catalytic asymmetric synthesis methods remains a critical challenge. Herein, we report the asymmetric synthesis of calix[4]arenes featuring inherent or both inherent and axial chirality via a cobalt-catalyzed C-H activation/annulation strategy in high yield with excellent enantio- and diastereoselectivity (up to > 99% ee and > 20:1 dr). Electrooxidation was also suitable for this transformation to obviate the sacrificial metal oxidants, underscoring the environmentally friendly potential of this approach. A key octahedral cobaltacycle intermediate was synthesized and characterized, providing valuable insights into the mode of enantio- and diastereocontrol of this protocol. Noteworthy photoluminescence quantum yields of up to 0.94 were measured, underscoring the potential of these compounds in the domain of organic fluorescent materials.

The preliminary study of the effects of individual musculoskeletally stable position in the treatment of temporomandibular disorders.

BACKGROUND: Temporomandibular Disorders (TMD) is the dysfunction of group of muscles and bones in the joint area, the main symptoms of TMD are the pain of the chewing muscles and (or) the temporomandibular joints, mandibular movement disorders and joint noise. This study was designed to explore the therapeutic effects following Individual Musculoskeletally Stable (IMS) position stabilization splint therapy for TMD patients using Fricton index, cone beam computed tomography (CBCT) and surface-Electromyogram (sEMG). METHODS: In this study, we enrolled 31 TMD patients (ranging from 18 to 26 years old, including 7 males and 24 females), first Fricton index was used to evaluate the clinical curative effect of TMD with the treatment of IMS stabilization splint; then CBCT was used to observe the TMJ condylar position changes of TMD before and after the treatment of IMS stabilization splint; finally sEMG was used to observe the changes of electromyography of anterior temporalis (AT) and masseter muscles (MM) of TMD before and after the treatment of IMS stabilization splint. RESULTS: The course of treatment was 6-8 months, with an average of 7.6 months. After the IMS stabilization splint treatment, TMD symptoms relieved, especially in pain, mandibular movement disorder, but still slightly inferior in the treatment of joint noise. And there was a statistically significant difference in the anterior and inner joint space, the condyle had the tendency of moving forward and outward. AT presented reduction significantly of EMG value at rest position after treatment. CONCLUSIONS: IMS stabilization splint is a therapeutic reversible treatment for TMD, especially for pain and mandibular movement disorder; it produces effects of forward and outward condylar movement and elimination of the masticatory muscles antagonism.

Patient-reported outcomes measure for patients with cleft palate.

Cleft palate presents multifaceted challenges impacting speech, hearing, appearance, and cognition, significantly affecting patients' quality of life (QoL). While surgical advancements aim to restore function and improve appearance, traditional clinical measures often fail to comprehensively capture patients' experiences. Patient-reported outcomes measure (PROMs) have emerged as crucial tools in evaluating QoL, offering insights into various aspects such as esthetic results, speech function, and social integration. This review explores PROMs relevant to cleft palate complications, including velopharyngeal insufficiency, oronasal fistulas, maxillary hypoplasia, sleep-disordered breathing, and caregiver QoL. Additionally, the review highlights the need for cleft palate-specific scales to better address the unique challenges faced by patients. By incorporating PROMs, healthcare providers can achieve more personalized, patient-centered care, improve communication, and enhance treatment outcomes. Future research should focus on developing and validating specialized PROMs to further refine patient assessments and care strategies.

Hongjin Xiaojie Capsule, a Chinese patent medicine, for treating moderate to severe cyclical breast pain: A single-blind randomized controlled trial.

BACKGROUND: Moderate to severe breast pain has major effects on the quality of life for patients. Patent Chinese medicines are widely used in the treatment of breast pain due to their stable dosage form and good efficacy. OBJECTIVE: To evaluate the beneficial effects and safety of Hongjin Xiaojie Capsule (HJXJC), a Chinese patent medicine, for the treatment of cyclical breast pain. DESIGN, SETTING, PARTICIPANTS AND INTERVENTION: This is a multicenter, single-blind randomized controlled trial conducted in 3 medical centers in China from 2019 to 2021. Patients with moderate to severe cyclic breast pain were randomly divided into the intervention group (who took HJXJC, four capsules per dose, three times a day for 12 weeks) and the control group (waiting for the treatment) in a 1:1 ratio. MAIN OUTCOME MEASURES: The primary outcome was pain duration, and the patients recorded measurements at baseline and at the end of weeks 4, 8, 12 and 16 on a patient log card. RESULTS: The full analysis set (FAS) population included 298 participants (intervention group, n = 150; control group, n = 148), while the per-protocol analysis set (PPS) included 274 participants. After 12 weeks, the duration of breast pain was significantly shorter in the intervention group (FAS: mean difference, -6.69; 95% CI, -7.58 to -5.80; P < 0.01, vs control. PPS: mean difference, -7.09; 95% CI, -8.01 to -6.16; P < 0.01, vs control). The Short-form McGill Pain Questionnaire (SF-MPQ) scores were significantly lower in the intervention group (FAS: mean difference, -12.55; 95% CI, -13.90 to -11.21; P < 0.01, vs control. PPS: mean difference, -13.07; 95% CI, -14.48 to -11.66; P < 0.01, vs control). The above indicators continued to be significantly different through week 16. Moreover, in the intervention group, breast lumps shrank after 12 weeks and the size of breast lumps was statistically smaller than that in the control group (P < 0.05), whereas the sizes of breast nodules and uterine fibroid showed no statistically significant difference compared with the control group (P > 0.05). At weeks 8 and 12, the dysmenorrhea scores in the intervention group were lower than those in the control group (P < 0.05). No obvious adverse reactions were observed in any group. CONCLUSION: HJXJC can significantly shorten the duration of breast pain, reduce breast pain, reduce the size of breast lumps, and relieve dysmenorrhea. However, it has no significant effect on the size of breast nodules or uterine fibroid. TRIAL REGISTRATION: This trial has been registered at the ISRCTN Registry. Number: ISRCTN44184398. PLEASE CITE THIS ARTICLE AS: Zhang Q, Fan YY, Wu XQ, Huo YD, Wang CH, Liang SB, Wang T, Zhong R, Wang X, Lai BY, Pei XH, Liu JP. Hongjin Xiaojie Capsule, a Chinese patent medicine, for treating moderate to severe cyclical breast pain: A single-blind randomized controlled trial. J Integr Med. 2024; Epub ahead of print.

Update on evidence-based clinical application of sodium-glucose cotransporter inhibitors: Insight to uncommon cardiovascular disease scenarios in diabetes.

In this paper, we concentrate on updating the clinical research on sodium-glucose cotransporter inhibitors (SGLTis) for patients with type 2 diabetes who have heart failure with a preserved injection fraction, acute heart failure, atrial fibrillation, primary prevention of atherosclerotic cardiovascular disease/cardiovascular disease, and acute myocardial infarction. We searched the data of randomized controlled trials and meta-analyses of SGLTis in patients with diabetes from PubMed between January 1, 2020 and April 6, 2024 for our review. According to our review, certain SGLTis (empagliflozin, dapagliflozin, canagliflozin, and tofogliflozin), but not sodium-glucose cotransporter 1 inhibitor (SGLT1i), exhibit relatively superior clinical safety and effectiveness for treating the abovementioned diseases. Proper utilization of SGLTis in these patients can foster clinical improvement and offer an alternative medication option. However, clinical trials involving SGLTis for certain diseases have relatively small sample sizes, brief intervention durations, and conclusions based on weak evidence, necessitating additional data. These findings are significant and valuable for providing a more comprehensive reference and new possibilities for the clinical utilization and scientific exploration of SGLTis.

Nickel(II)/BINOL-catalyzed enantioselective C-H activation via desymmetrization and kinetic resolution.

The field of nickel catalysis has witnessed remarkable growth in recent years. However, the use of nickel catalysts in enantioselective C-H activation remains a daunting challenge because of their variable oxidation states, intricate coordination chemistry, and unpredictable reactivity patterns. Herein, we report an enantioselective C-H activation reaction catalyzed by commercially available and air-stable nickel(II) catalyst. Readily available and simple (S)-BINOL is used as a chiral ligand. This operationally simple protocol enables the synthesis of planar chiral metallocenes in high yields with excellent enantioselectivity through desymmetrization and kinetic resolution. Air-stable planar chiral nickelacycle intermediates are first synthesized via enantioselective C-H nickelation and shown to be possible intermediates of the reaction. Deuterium-labeling studies, alongside the characterization and transformation of chiral nickel(II) species, suggest that C-H cleavage is the enantio-determining step. Moreover, the large-scale synthesis and diverse synthetic transformations underscore the practicality of this protocol.

[Distribution of ABO and Rh Blood Groups in Tibetan and Han Populations With Cleft Lip and Palate in a Tertiary Hospital in Western China]. / ä¸­å›½è¥¿éƒ¨æŸä¸‰ç”²åŒ»é™¢è—æ—ä¸Žæ±‰æ—å”‡è ­è£‚æ‚£è€ ABO血型及Rhè¡€åž‹åˆ†å¸ƒç ”ç©¶.

Objective: Congenital cleft lip and palate is a common birth defect that seriously affects the lives of the afflicted children and their families. Previously, no research has been done to investigate the pathogenic characteristics of cleft lip and palate among ethnic minorities, for example, Tibetans, a minority ethnic group with a large population in China. This study aims to investigate the relationship between the occurrence of cleft lip and palate in Tibetans and Han Chinese in western China and the distribution of ABO blood groups and Rh blood groups to provide a theoretical basis for the precise prevention and treatment of cleft lip and palate. Methods: In this study, statistics on Tibetan patients with cleft lip and palate, some Han patients with cleft lip and palate, and normal controls from western China were retrospectively collected. All participants were patients from West China Stomatology Hospital, Sichuan University. All patients with cleft lip and palate received treatment at the hospital between January 2016 and September 2023. The normal controls were outpatients or inpatients who did not have cleft lip and palate, and who received treatment at the hospital between January 2020 and October 2023. Information on the A, B, O, and AB blood groups and Rh positive and negative blood groups of the patients was collected and compared with that of the normal controls. The incidence of different phenotypes, including cleft lip alone, cleft palate alone, and cleft lip with cleft palate, in patients of blood groups A, B, O and AB were statistically analyzed by Chi-square test. Results: A total of 1227 Tibetan patients with cleft lip and palate, 4064 Han patients with cleft lip and palate, and 5360 normal controls were included in the study. Among all the patients with cleft lip and palate, 1863 had cleft lip alone, 1425 had cleft palate alone, and 2003 had cleft lip with cleft palate. The ABO blood group distribution of Tibetan patients with cleft lip and palate was characterized as O>B>A>AB, with Rh positive blood group accounting for 100%, blood type O accounting for 41.15%, and blood type B accounting for 30.64%. The blood group distribution of the Han patients with cleft lip and palate was characterized as O>A>B>AB, with Rh positive blood group accounting for 99.58%, blood type O accounting for 35.78%, and type A accounting for 30.54%. There was a significant difference in ABO blood groups between Tibetan and Han patients with cleft lip and palate (P<0.005), but no significant difference in Rh blood groups. The ABO blood group distribution of the Tibetan patients with cleft lip and palate showed an obvious difference from that of the control group, while those of the Han patients with cleft lip and cleft palate and the control group did not show obvious differences. In the analysis of the subtypes, it was found that the blood group distribution in the subtypes of cleft lip alone, cleft palate alone, and cleft lip with cleft palate in the Tibetan population was O>B>A>AB, while that in the Han Chinese population was O>A>B>AB. There were differences in blood group distribution between Tibetans and Hans of the subtypes of cleft lip alone and cleft lip with cleft palate (P<0.001), but there was no difference in blood group distribution in the population of cleft palate-only subtype. The proportion of blood type O in Tibetan patients with cleft lip and palate was significantly higher than that in the Han patients with cleft lip and palate. The blood group distribution of Tibetan patients with cleft lip and palate in Sichuan Province, Xizang Autonomous Region, and Qinghai Province was always O>B>A>AB. Tibetan patients from Shiqu County and Baiyu County, Ganzi Tibetan Autonomous Prefecture and Chaya County, Qamdo City were predominantly of blood type B, and those from other regions were mainly of blood type O. Conclusion: There were significant differences in the phenotype composition and ABO blood group distribution between the Tibetan and Han populations with cleft lip and palate in western China. The distribution of blood group O in the population with cleft lip and palate was higher than that in the normal population, and the same trend was observed for different phenotypes. However, differences between Tibetan and Han populations in ABO blood group distribution were only found in the phenotypes of cleft lip only and cleft lip with palate. Tibetans with blood type O are more prone to cleft lip deformity than Han people, and the effect in the phenotype of cleft lip with palate is less pronounced than that in the phenotype of cleft lip only.

Implication of locus coeruleus dysfunction in Prader-Willi syndrome: Insights from a mouse model.

Prader-Willi syndrome (PWS) is a multisystemic disorder. Notably, many characteristic symptoms of PWS are correlated with locus coeruleus norepinephrine system (LC-NE) dysfunction, including impairment in arousal, learning, pain modulation, and stress-induced negative affective states. Although electrophysiological experiments in necdin-deficient mice, an established PWS animal model, have revealed decreased spontaneous neuronal firing activity in the LC and impaired excitability, the behavioral phenotypes related to LC-NE dysfunction remain unexplored. In this study, heterozygous necdin-deficient mice (B6.Cg-Ndntm1ky) were bred from wild-type (WT) females to generate WT (+m/+p) and heterozygous (+m/-p) animals. Compared to WT mice, Ndn + m/-p mice demonstrated impaired visual-spatial memory in the Y-maze test, reduced social interaction, impaired sexual recognition, and shorter falling latency on the Rotarod. Using the open field test (OFT) and elevated plus maze (EPM), we observed similar locomotion activity of Ndn + m/-p and WT mice, but Ndn + m/-p mice were less anxious. After acute restraint, Ndn + m/-p mice exhibited significant impairment in stress-induced anxiety. Additionally, the plasma norepinephrine surge following exposure to acute restraint stress was also impaired. Pretreatment with atomoxetine, a norepinephrine reuptake inhibitor aimed to enhance LC function, restored Ndn + m/-p mice to exhibit a normal response to acute restraint stress. Furthermore, by employing chemogenetic approaches to facilitate LC neuronal firing, post-stress anxious responses were also partially rescued in Ndn + m/-p mice. These data strongly suggest that LC dysfunction is implicated in the pathogenesis of stress-related neuropsychiatric symptoms in PWS. Manipulation of LC activity may hold therapeutic potential for patients with PWS.

Single vs. Double-Opposing Z-Plasty: Evaluating Their Impact on Palatoplasty Postoperative Outcomes.

BACKGROUND: The double-opposing Z-plasty is a fundamental approach for cleft palate repair. Recently, some surgeons have begun implementing a single Z-Plasty, igniting discussions on the most effective technique for enhancing postoperative outcomes. Consequently, this study sought to evaluate the outcomes of employing single and double Z-plasties within the modified Sommerlad-Furlow technique. METHODS: 116 cleft palate patients undergoing primary surgical repair were divided into two groups: those treated with the Sommerlad-Furlow method using a double-opposing Z-plasty (S.F.2.Z.P. group, n = 58) and those receiving a single nasal Z-plasty (S.F.1.Z.P. group, n = 58). Data on cleft type and width, soft palate length, palatal fistula, and velopharyngeal function were collected. Mann-Whitney test compared the mean values between groups. RESULTS: The S.F.2ZP group demonstrated a statistically significant increase in soft palate length compared to those in the S.F.1ZP group (p = 0.008). However, the S.F.1ZP group demonstrated adequate soft palate length (7.9 ± 2.8 mm) compared to the S.F.2ZP group (9.3 ± 2.8 mm). The velopharyngeal function was good in both groups, with no significant differences (P = 0.52). While the proper velopharyngeal closure was 81% in the S.F.1ZP group and 87.9% in the S.F.2ZP group, velopharyngeal insufficiency was 10.3% and 5.2%, respectively. The rates of persistent palatal fistula were 5.2% in the S.F.1ZP group and 3.4% in the S.F.2ZP group, with no significant differences found between both groups (P = 0.64). CONCLUSIONS: There were no significant differences in crucial outcomes such as velopharyngeal function and the incidence of persistent palatal fistulas, indicating the effectiveness of both techniques. While the double-opposing Z-plasty demonstrated a statistically significant increase in soft palate length, the a nasal Z-plasty demonstrated adequate soft palate length which sufficiently enables effective velopharyngeal closure. These outcomes suggest that a single Z-plasty is both effective and easy to perform, making it a valuable surgical approach for achieving the desired outcomes.. CLINICAL RELEVANCE: The current study suggests that although the soft palate may not be as elongated with nasal Z-plasty alone compared to the double Z-plasty, it sufficiently enables effective velopharyngeal closure.

5-year Long-term Outcome of Unilateral Cleft Rhinoplasty in Patients with Secondary Nasal Deformity: Optimal Indication of Tajima Technique.

BACKGROUND: This study aimed to investigate the timing of and indications for the Tajima reverse U incision for correcting secondary unilateral cleft nasal deformities. METHODS: Non-syndromic patients with secondary cleft lip and nasal deformity who received Tajima reverse-U incision rhinoplasty were grouped by age (4-13 years, n=56;13-18 years, n=22; >18 years, n=18) and severity of deformity (mild deformity, n=7; moderate deformity=22; severity deformity=67) during 5-year follow-up. Face-Q assessment, a rating scale, and nasal symmetry measurements were employed in this study. RESULTS: Ninety-six patients completed the FACE-Q assessment for the nose and nostril. The results showed higher satisfaction with nostril appearance 1-week after surgery (85.95±13.01) compared with pre-operation (79.72±11.89) and maintained 5-year follow-up (82.61±14.06). Significant differences were observed in five nasal parameters (nasal height ratio, one-fourth media part of nostril height ratio, nasal sill height ratio, columellar angle, and inner nostril height-to-width ratio (cleft)) for 1-week postoperatively and the corrected outcome of the Tajima technique was maintained 5 years after surgery in aged 4-13 years group. The same statistically significant changes were found in nasal sill height ratio in mild deformity group and nostril width ratio, one-fourth media part of nostril height ratio, columellar angle, and inner nostril height-to-width ratio (cleft) in moderate deformity group. CONCLUSION: The Tajima procedure was beneficial for preadolescent children and children with mild to moderate unilateral cleft nasal deformities.

Pd-Catalyzed Atroposelective C-H Olefination: Diverse Synthesis of Axially Chiral Biaryl-2-carboxylic Acids.

Axially chiral carboxylic acids are important motifs in chiral catalysts and ligands. We herein reported the synthesis of axially chiral carboxylic acids via Pd(II)-catalyzed atroposelective C-H olefination using carboxylic acid as the native directing group. A broad range of axial chiral biaryl-2-carboxylic acids were synthesized in good yields with high enantioselectivities (up to 84% yield with 99% ee). Gram-scale reaction and further transformation reactions also provide a platform for synthetic applications of this method.

Asymmetric Dearomatization of Indoles through Cobalt-Catalyzed Enantioselective C-H Functionalization Enabled by Photocatalysis.

Photocatalysis holds a pivotal position in modern organic synthesis, capable of inducing novel reactivities under mild and environmentally friendly reaction conditions. However, the merger of photocatalysis and transition-metal-catalyzed asymmetric C-H activation as an efficient and sustainable method for the construction of chiral molecules remains elusive and challenging. Herein, we develop a cobalt-catalyzed enantioselective C-H activation reaction enabled by visible-light photoredox catalysis, providing a synergistic catalytic strategy for the asymmetric dearomatization of indoles with high levels of enantioselectivity (96 % to >99 % ee). Mechanistic studies indicate that the excited photocatalyst was quenched by divalent cobalt species in the presence of Salox ligand, leading to the formation of catalytically active chiral Co(III) complex. Moreover, stoichiometric reactions of cobaltacycle intermediate with indole suggest that the irradiation of visible light also play a critical role in the dearomatization step.

Cephalometric Pharyngeal Morphology in Adults with Unoperated Cleft Palate.

OBJECTIVE: The aim of this study was to cephalometrically evaluate the pharyngeal morphology in adults with unoperated Submucous Cleft Palate (SMCP), adults with unoperated Overt Cleft Palate (OCP), and adults without clefts. DESIGN: This study employed a retrospective cross-sectional design. Lateral cephalometric radiography was performed on three groups of adults: 1) 29 with unrepaired SMCP; 2) 41 with unrepaired OCP; and 3) 39 without clefts, who served as controls. One-way ANOVA and rank-sum tests were used for intergroup comparisons. P value was set at .05. RESULTS: The soft palate length and the ratio of soft palate length to pharyngeal depth were significantly lower in subjects with unoperated SMCP and OCP than in non-cleft controls. Significant differences were also observed in pharyngeal depth, nasopharyngeal depth, and posterior pharyngeal wall thickness between subjects with unoperated OCP and non-cleft controls. CONCLUSIONS: Pharyngeal morphology differs significantly between individuals with and without clefts, particularly in soft palate length and the ratio of soft palate length to pharyngeal depth.

Chiral dinitrogen ligand enabled asymmetric Pd/norbornene cooperative catalysis toward the assembly of C-N axially chiral scaffolds.

C - N axially chiral compounds have recently attracted significant interest among synthetic chemistry community due to their widespread application in pharmaceuticals, advanced materials and organic synthesis. Although the emerging asymmetric Catellani reaction offers great opportunity for their modular and efficient preparation, the only operative chiral NBE strategy to date requires using half stoichiometric amount of chiral NBE and 2,6-disubstituted bromoarenes as electrophiles. We herein report an efficient assembly of C-N axially chiral scaffolds through a distinct chiral ligand strategy. The crucial chiral source, a biimidazoline (BiIM) chiral dinitrogen ligand, is used in relatively low loading and permits the use of less bulky bromoarenes. The method also features the use of feedstock plain NBE, high reactivity, good enantioselectivity, ease of operation and scale-up. Applications in the preparation of chiral optoelectronic material candidates featuring two C-N chiral axes and a chiral ligand for asymmetric C-H activation have also been demonstrated.

Force Balance Reconstruction of the Orbicularis Oris in Secondary Unilateral Cleft Lip Deformity.

BACKGROUND: Secondary unilateral cleft lip deformities are commonly observed in patients with cleft lip and traditional surgical methods can't completely tackle this problem. The purpose of this study was to evaluate the outcomes of a novel surgical technique using force balance reconstruction of the orbicularis oris. METHODS: 53 patients with secondary unilateral cleft lip deformity were included in this study, in which the orbicularis oris muscle was reconstructed symmetrically to achieve optimal force balance. Photometric 2d indexes were employed to evaluate the outcome of 27 patients, and 3d indexes for the remaining 26 patients. Aesthetic evaluation and parent-patient satisfaction surveys were also recorded. RESULTS: Significant differences were found in the following: (1) LH (the lip height), LW (the lip width), D1(the vertical distance from the white roll to the vermilion bottom at the christa philtra points) and D2(the vertical distance from the christa philtra points to the facial midline) when comparing preoperative and postoperative 2D images; (2) LH, LW, D1 and D2 when comparing preoperative and follow-up 2D images; (3) RMS (root mean of square) when comparing preoperative and postoperative 3D images. Aesthetic evaluation in the follow-up period was a mean of 4.29, while parent-patient satisfaction of the overall appearance was a mean of 4.41. CONCLUSIONS: The results suggest this new muscle reconstruction technique can significantly improve the surgical outcome of secondary unilateral cleft lip deformities. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ."

Central Channelopathies in Obesity.

As obesity has raised heightening awareness, researchers have attempted to identify potential targets that can be treated for therapeutic intervention. Focusing on the central nervous system (CNS), the key organ in maintaining energy balance, a plethora of ion channels that are expressed in the CNS have been inspected and determined through manipulation in different hypothalamic neural subpopulations for their roles in fine-tuning neuronal activity on energy state alterations, possibly acting as metabolic sensors. However, a remaining gap persists between human clinical investigations and mouse studies. Despite having delineated the pathways and mechanisms of how the mouse study-identified ion channels modulate energy homeostasis, only a few targets overlap with the obesity-related risk genes extracted from human genome-wide association studies. Here, we present the most recently discovered CNS-specific metabolism-correlated ion channels using reverse and forward genetics approaches in mice and humans, respectively, in the hope of illuminating the prospects for future therapeutic development.

Cobalt-Catalyzed Domino Transformations via Enantioselective C-H Activation/Nucleophilic [3 + 2] Annulation toward Chiral Bridged Bicycles.

Selective synthesis of chiral bridged (hetero)bicyclic scaffolds via asymmetric C-H activation constitutes substantial challenges due to the multiple reactivities of strained bicyclic structures. Herein, we develop the domino transformations through an unprecedented cobalt-catalyzed enantioselective C-H activation/nucleophilic [3 + 2] annulation with symmetrical bicyclic alkenes. The methods offer straightforward access to a wide range of chiral molecules bearing [2.2.1]-bridged bicyclic cores with four and five consecutive stereocenters in a single step. Two elaborate salicyloxazoline (Salox) ligands were synthesized based on the rational design and mechanistic understanding. The well-defined chiral pockets generated from asymmetric coordination around the trivalent cobalt catalyst direct the orientation of bicyclic alkenes, leading to excellent enantioselectivity.