Catalytic Tandem C–C Bond Formation/Cleavage of Cyclopropene for Allylzincation of Aldehydes or Aldimine Using Organozinc Reagents
摘要:
The tandem allylation of aldehydes or an aldimine with allylzinc intermediates derived from organozinc reagents and cyclopropenes is described. The present three-component reaction involves carbozincation of cyclopropene and sequential cleavage of a cyclopropylzinc intermediate in situ without a transition-metal catalyst. The allylzinc intermediates generated in situ, which is an alpha,beta-unsaturated acylanion equivalent, gave the corresponding homoallylic alcohols or amine in good yields.
Catalytic Tandem C–C Bond Formation/Cleavage of Cyclopropene for Allylzincation of Aldehydes or Aldimine Using Organozinc Reagents
作者:Takeo Nakano、Kohei Endo、Yutaka Ukaji
DOI:10.1021/ol500208r
日期:2014.3.7
The tandem allylation of aldehydes or an aldimine with allylzinc intermediates derived from organozinc reagents and cyclopropenes is described. The present three-component reaction involves carbozincation of cyclopropene and sequential cleavage of a cyclopropylzinc intermediate in situ without a transition-metal catalyst. The allylzinc intermediates generated in situ, which is an alpha,beta-unsaturated acylanion equivalent, gave the corresponding homoallylic alcohols or amine in good yields.
Silver-Catalyzed Allylation of Ketones and Intramolecular Cyclization through Carbene Intermediates from Cyclopropenes Under Ambient Conditions
作者:Takeo Nakano、Kohei Endo、Yutaka Ukaji
DOI:10.1002/asia.201501196
日期:2016.3.4
Tandem C−C bond formation was achieved through silver‐catalyzed ring‐opening of cyclopropenesvia carbene intermediates. The reaction of cyclopropenes in the presence of a silver catalyst gave indene derivatives under ambient conditions. In contrast, the insertion of organozinc reagents to silver carbene or allylic cation intermediates afforded allylmetal intermediates for the tandem allylation of