亚砜及亚磺酰胺类配体催化不对称反应的新进展

亚砜及亚磺酰胺类化合物作为手性配体催化不对称反应是目前研究最为活跃的领域之一,苯环骨架以及链状骨架的亚砜及亚磺酰胺类手性配体相继成功地用于不对称反应中.主要综述了近年来含亚砜及亚磺酰胺类的手性配体催化不对称反应的研究进展.     

Rhodium‐Catalyzed C?H Annulation of Nitrones with Alkynes: A Regiospecific Route to Unsymmetrical 2,3‐Diaryl‐Substituted Indoles

The direct C H annulation of anilines or related compounds with internal alkynes provides straightforward access to 2,3‐disubstituted indole products. However, this transformation proceeds with poor regioselectivity in the synthesis of unsymmetrically 2,3‐diaryl substituted indoles. Herein, we report the rhodium(III)‐catalyzed C H annulation of nitrones with symmetrical diaryl alkynes as an alternative method to prepare 2,3‐diaryl‐substituted N‐unprotected indoles with two different aryl groups. One of the aryl substituents is derived from NC‐aryl ring of the nitrone and the other from the alkyne substrate, thus providing the indole products with exclusive regioselectivity.     

Silver-catalyzed [3+2+1] annulation of aryl amidines with benzyl isocyanide

A silver-catalyzed [3+2+1] annulation of amidines with benzyl isocyanide toward 2,4-diaryl-1,3,5-triazines was developed. A variety of symmetrical and unsymmetrical products were obtained in moderate to good yields. This work also features an oxidant-free approach to 2,4-disubstituted triazines.     

Direct oxidative phosphonylation of amines under metal-free conditions

Direct oxidation coupling of tertiary amines and dialkyl- or diphenyl-substituted phosphonates was developed. The reaction was mediated by DDQ under room temperature. Various phosphonates and N-aryl tetrahydroisoquinolines were tolerated in this reaction, and α-aminophosphonates were obtained with up to 99% yield.     

A class of benzene backbone-based olefin-sulfoxide ligands for Rh-catalyzed enantioselective addition of arylboronic acids to enones

A class of readily available and easily tunable benzene backbone-based olefin-sulfoxide ligands was developed for the rhodium-catalyzed asymmetric conjugate addition reaction of arylboronic acids to enones with up to 97% yield and 97% ee.     

路易斯酸碱催化的外消旋体(动态)动力学拆分反应

外消旋体的(动态)动力学拆分反应是制备手性化合物的重要方法之一.反应可以通过酶催化或非酶催化的手段来实现,也可以通过两种方法的有机结合来进行.在非酶催化反应中,路易斯酸碱催化是比较常用的方法,它们被广泛地用于多种外消旋体的(动态)动力学拆分反应中,目前在该领域取得了很大的进展.本文讨论了路易斯酸及路易斯碱催化体系在外消旋体(动态)动力学拆分反应中应用的最新进展.     

A new filled function method for an unconstrained nonlinear equation

In this paper, we transform an unconstrained system of nonlinear equations into a special optimization problem. A new filled function is constructed by employing the special properties of the transformed optimization problem. Theoretical and numerical properties of the proposed filled function are investigated and a solution of the algorithm is proposed. Under some conditions, we can find a solution or an approximate solution to the system of nonlinear equations in finite iterations. The implementation of the algorithm on six test problems is reported with satisfactory numerical results.     

基于甲磺酰基的磺酰胺-氨醇作为催化醛的不对称炔基化反应新配体

 以商业易得的 (–)-麻黄碱、(+)-伪麻黄碱和各种手性氨醇为主要原料, 经过简单的两步反应, 合成了一系列基于甲磺酰基的磺酰胺-氨醇 (SAA) 配体, 并将其用于催化苯乙炔基锌对醛的不对称加成反应. 在没有 Ti(OiPr)4 等金属试剂的条件下, 配体表现出较好的不对称诱导能力, 取得了高达 83% ee.