A general strategy for the synthesis of arylthio cyclopropyl carbaldehydes and ketones via a Brønsted acid catalyzed arylthiol addition/ring contraction reaction sequence has been exploited. The procedure led to a wide panel of cyclopropyl carbaldehydes in generally high yields and with broad substrate scope. Mechanistic aspects and synthetic applications of this procedure were investigated.
Nickel/N-Heterocyclic Carbene Complex-Catalyzed Enantioselective Redox-Neutral Coupling of Benzyl Alcohols and Alkynes to Allylic Alcohols
作者:Yuan Cai、Jia-Wen Zhang、Feng Li、Jia-Ming Liu、Shi-Liang Shi
DOI:10.1021/acscatal.8b04198
日期:2019.1.4
The nickel-catalyzed enantioselective redox-neutral coupling of alcohols and alkynes to access chiral allylic alcohols is reported. The reaction proceeds via a hydrogen transfer process under ambient temperature, converting abundant feedstock alcohols and alkynes to chiral allylic alcohols with high stereoselectivities in one chemical step. Key to the success of this process was the development of
Scandium-Catalyzed Regio- and Stereospecific Methylalumination of Silyloxy/Alkoxy-Substituted Alkynes and Alkenes
作者:Masanori Takimoto、Saori Usami、Zhaomin Hou
DOI:10.1021/ja909126k
日期:2009.12.30
Various alkynes and alkenes having a tethered ether group undergo methylalumination reactions with unprecedented regio- and stereoselectivity in the presence of a cationic half-sandwich alkylscandium species as a catalyst. The oxygen atom of the ether group plays an important role in controlling the selectivity, possibly by coordinating to the metal center. Even when a bulky tertbutyl(diphenyl)silyloxy group is used as the tether group, there is no loss of selectivity.
Nickel-Catalyzed Redox-Economical Coupling of Alcohols and Alkynes to Form Allylic Alcohols
We have developed a redox-economical coupling reaction of alcohols and alkynes to form allylic alcohols under mild conditions. The reaction is redox-neutral as well as redox-economical and thus free from any additives such as a reductant or an oxidant. This atom-economical coupling can be applied for the conversion of both aliphatic and benzylic alcohols to the corresponding substituted allylic alcohols in a single synthetic operation.