Rh(III)-Catalyzed C–H Cyclization of Arylnitrones with Diazo Compounds: Access to 3-Carboxylate Substituted<i>N</i>-Hydroxyindoles
作者:Yazhou Li、Jian Li、Xiaowei Wu、Yu Zhou、Hong Liu
DOI:10.1021/acs.joc.7b01393
日期:2017.9.1
Recently, N-hydroxyindole derivatives have received much interest because of their unique structural motif and various biological activities. In this study, we report the first example of a Rh(III)-catalyzed reaction of arylnitrones with α-diazoketoesters or α-diazodiketones to produce N-hydroxyindole derivatives. Intriguingly, we could build the N-hydroxyindole scaffold by blocking the cleavage of
Rhodium(III)-Catalyzed Synthesis of Cinnolinium Salts from Azobenzenes and Diazo Compounds
作者:Xiaohong Chen、Guangfan Zheng、Guoyong Song、Xingwei Li
DOI:10.1002/adsc.201800326
日期:2018.8.6
A Rh(III)‐catalyzed C−H activation of azobenzenes in the coupling with diazo compounds has been realized, providing a straightforward strategy to access functionalized cinnolinium triflates in high yields. This protocol features silver free mild reaction conditions and compatibility with diverse functional groups. The coupling proceeds via initial Rh(III)‐catalyzed C−H alkylation, followed by zinc
Regioselective Syntheses of 1,2-Benzothiazines by Rhodium-Catalyzed Annulation Reactions
作者:Ying Cheng、Carsten Bolm
DOI:10.1002/anie.201501583
日期:2015.10.12
Rhodium‐catalyzed directed carbene insertions into aromatic CH bonds of S‐aryl sulfoximines lead to intermediates, which upon dehydration provide 1,2‐benzothiazines in excellent yields. The domino‐type process is regioselective and shows a high functional‐group tolerance. It is scalable, and the only by‐products are dinitrogen and water. Three illustrative transformations underscore the synthetic
Enantioselective Synthesis of Chiral‐at‐Sulfur 1,2‐Benzothiazines by Cp<sup>x</sup>Rh<sup>III</sup>‐Catalyzed C−H Functionalization of Sulfoximines
作者:Yang Sun、Nicolai Cramer
DOI:10.1002/anie.201810887
日期:2018.11.19
attractive structural motifs in drug discovery. A direct catalytic enantioselective method for the synthesis of sulfur‐chiral 1,2‐benzothiazines from readily accessible diaryl sulfoximines is presented. Rhodium(III) complexes equipped with chiral cyclopentadienyl ligands and paired with suitable carboxylic acid additives engage in an enantiodetermining C−H activation directed by the sulfoximine group. Subsequent
Enantiodivergent Desymmetrization in the Rhodium(III)‐Catalyzed Annulation of Sulfoximines with Diazo Compounds
作者:Bingxue Shen、Boshun Wan、Xingwei Li
DOI:10.1002/anie.201810472
日期:2018.11.19
reactions of arenes have relied on the employment of chiral RhIII/IrIII cyclopentadienyl catalysts, the introduction of chiral carboxylic acids to achiral Cp*RhX2 catalysts, and the integration of both strategies. Despite considerable progress, each reaction only provided a specific configuration of the enantioenriched product when using a particular chiral catalyst. Reported in this work is the enantiodivergent
Rh III和Ir III催化的芳烃不对称CH功能化反应依赖于使用手性Rh III / Ir III环戊二烯基催化剂,将手性羧酸引入非手性Cp * RhX 2催化剂,以及两者的结合策略。尽管取得了相当大的进步,但是当使用特定的手性催化剂时,每个反应仅提供了对映体富集产物的特定构型。这项工作报道了Rh III对亚砜亚砜与各种重氮化合物的对映异构偶联催化的非对称环形。通过明智地选择非手性羧酸可以使对映体发散,并且对映体选择性与羧酸和磺胺基亚胺的空间偏倚相关。