Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
作者:Qiuyue Wu、Ziyang Dong、Jiaxi Xu、Zhanhui Yang
DOI:10.1039/d1ob00116g
日期:——
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved and a mechanistic investigation is performed, with an inverse KIE of 0.49 obtained.
The first copper-catalyzed imidovinylation of alkynes has been developed, which grants facile access to various (E)-2-imido-2,4-dienals with high stereoselectivity under mild conditions. This transformation also represents the first 1,3-carbon migration of propargylic alcohols and their derivatives.
Cobalt‐Catalyzed Reductive Dimethylcyclopropanation of 1,3‐Dienes
作者:Jacob Werth、Christopher Uyeda
DOI:10.1002/anie.201807542
日期:2018.10.15
variant of the Simmons–Smith reaction that enables the efficient dimethylcyclopropanation of 1,3‐dienes using a Me2CCl2/Zn reagent mixture. The reactions proceed with high regioselectivity based on the substitution pattern of the 1,3‐diene. The products are vinylcyclopropanes, which serve as substrates for transition‐metal‐catalyzed ring‐opening reactions, including 1,3‐rearrangement and [5+2] cycloaddition
Dilithiated 3-tosylpropanal dimethyl acetal as β,β-acylvinyl dianion or homoenolate dianion equivalent
作者:Pedro Bonete、Carmen Nájera
DOI:10.1016/s0040-4020(96)00072-5
日期:1996.3
3,3-Dilithio-1,1-dimethoxy-3-tosylpropane (6) reacts with mono and dielectrophiles to give dialkylated products 7 and carbocyclic derivatives 8, respectively. Hydrolysis of the acetal function followed by DBU dehydrosulfinylation of these products affords beta,beta-disubstituted propenal derivatives 11 and 12. Reductive desulfonylation of compounds 8g-j provides beta,beta-disubstituted propanal acetals 14.