vinyl dichlorides and electron deficient amides as the starting material is described. In the absence of transition-metal catalyst, the reaction proceeds under mild reaction conditions in open air and thus rendering a convenient operation. This strategy is not only suitable for both terminal and internal ynamide synthesis but also amenable for large-scale preparation. Broad substrate scopes with respect
<i>C</i><sub>2</sub>-Symmetric Dinickel Catalysts for Enantioselective [4 + 1]-Cycloadditions
作者:Michael J. Behlen、Christopher Uyeda
DOI:10.1021/jacs.0c08262
日期:2020.10.14
methylenecyclopentenes, and the exocyclic alkene is generally obtained with high Z selectivity. E and Z dienes react in a stereoconvergent fashion, providing cycloadducts with the same sense of absolute stereochemistry and nearly identical ee values. This feature allows dienes that are commercially available as E/Z mixtures to be used as substrates for the cycloaddition. A DFT model for the origin of asymmetric
二镍萘啶-双(恶唑啉)催化剂促进亚乙烯基和1,3-二烯的对映选择性分子间[4 + 1]-环加成。该反应的产物是亚甲基环戊烯,通常以高Z选择性获得环外烯烃。E 和 Z 二烯以立体收敛方式反应,提供具有相同绝对立体化学意义和几乎相同 ee 值的环加合物。该特征允许将作为 E/Z 混合物市售的二烯用作环加成的底物。提供了非对称归纳起源的 DFT 模型。
A Novel Synthetic Approach to Dichlorostyrenes
作者:Alexey V Shastin、Vasily N Korotchenko、Valentine G Nenajdenko、Elisabeth S Balenkova
DOI:10.1016/s0040-4020(00)00606-2
日期:2000.8
We found that N-unsubstituted hydrazones of aromatic aldehydes can be easily converted to the corresponding 1,1-dichlorostyrenes in the reaction with carbontetrachloride using copper (I) chloride as catalyst. Factors affecting the route of the reaction and yields of the products were investigated. A proposed mechanism for the reaction is discussed.
Catalytic [5 + 1]-Cycloadditions of Vinylcyclopropanes and Vinylidenes
作者:Conner M. Farley、Kohei Sasakura、You-Yun Zhou、Vibha V. Kanale、Christopher Uyeda
DOI:10.1021/jacs.0c00356
日期:2020.3.11
1]-cycloaddition between a vinylcyclopropane and a vinylidene to provide methylenecyclohexenes bearing all-meta relationships. Vinylidene equivalents are generated from 1,1-dichloroalkenes using Zn as a stoichiometric reductant. Experimental observations are consistent with a mechanism involving a cobaltacyclobutane formed from a [2 + 2]-cycloaddition between a cobalt vinylidene and a vinylcyclopropane.
Pd(OAc)<sub>2</sub>/SPPh<sub>3</sub> accelerated activation of gem-dichloroalkenes for the construction of 3-arylchromones
作者:Jianming Liu、Weiwei Song、Yuanyuan Yue、Ren Liu、Hong Yi、Kelei Zhuo、Aiwen Lei
DOI:10.1039/c5cc06334e
日期:——
The Pd-catalyzed regioselective intramolecular nucleophilic substitution of gem-dichloroalkene derivatives with salicylaldehydes leading to the synthesis of 3-arylchromones has been developed.