Stereoselective synthesis of ε-lactones or spiro-heterocycles through NHC-catalyzed annulation: divergent reactivity by catalyst control
作者:Min Wang、Zi-Qiang Rong、Yu Zhao
DOI:10.1039/c4cc07788a
日期:——
NHC-catalyzed divergent annulation of enals with heterocyclic enones was developed to produce benzofuran/indole-containing ε-lactones or spiro-heterocycles in a highly diastereo- and enantioselective fashion.
Azonanes were prepared by a palladium-catalyzed (5 + 4) cycloaddition between activated vinylcyclopropanes and 1-azadienes. During this process, the vinylcyclopropane partner displayed an unusual reactivity and behaved as an all-carbon 1,5-dipole. A N,N-bidentate ligand was required to inhibit the formation of thermodynamic (3 + 2) cycloadducts.
Rhodium-Catalyzed Annulation of α-Imino Carbenes with α,β-Unsaturated Ketones: Construction of Multisubstituted 2,3-Dihydropyrrole/pyrrole Rings
作者:Xueji Ma、Li Liu、Jiaying Wang、Xianglin Xi、Xuemei Xie、Hangxiang Wang
DOI:10.1021/acs.joc.8b01835
日期:2018.12.7
An efficient annulation of α-imino rhodium carbenes with α,β-unsaturatedketones has been developed to generate multisubstituted 2,3-dihydropyrrole derivatives. Using the optimized catalyst, this approach is compatible with both cyclic and normal linear α,β-unsaturatedketones. Further detosylation in the presence of base could produce multisubstituted pyrroles. The new method has the potential to