formation reaction of simple NH-sulfoximines with 1,4,2-dioxazol-5-ones to produce diverse thiadiazine-1-oxides is reported. The reaction tolerates a broad range of functional groups under external oxidant-free conditions and only releases CO2 and H2O as the sole byproducts. The preliminary mechanistic studies revealed an electrophilic metalation pathway is likely involved in the reaction.
微波辅助的Cp * Co III催化的简单N H-亚磺酰亚胺与1,4,2-二恶唑-5-酮的直接C–H活化/双C–N键形成反应,生成各种噻二嗪-1-氧化物。被报道。在无外部氧化剂的条件下,该反应可耐受各种官能团,并且仅释放出CO 2和H 2 O作为唯一的副产物。初步的机理研究表明,该反应可能涉及亲电性金属化途径。
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。
Rhodium-catalyzed benzoisothiazole synthesis by tandem annulation reactions of sulfoximines and activated olefins
作者:Yang Li、Lin Dong
DOI:10.1039/c7ob02586f
日期:——
Rhodium(III)-catalyzed N-directed ortho C–H activation reactions have been developed for the synthesis of unique heterocyclic benzoisothiazoles. Herein, this novel tandem annulation approach can efficiently construct benzoisothiazole compoundsfrom free NH-sulfoximines and alkenes via C–H activation, olefination and subsequent intramolecular aza-Michael cyclization.
Enantioselectivesynthesis of benzothiadiazine-1-oxides has been achieved using an achiral cobalt(III) catalyst and a pseudo-C2-symmetric H8-binaphthyl chiralcarboxylicacid. The hybrid catalytic system enables a rapid access to benzothiadiazine-1-oxides from readily available sulfoximines and dioxazolones with high enantioselectivity.