Pd(ii)–SDP-catalyzed enantioselective 5-exo-dig cyclization of γ-alkynoic acids: application to the synthesis of functionalized dihydofuran-2(3H)-ones containing a chiral quaternary carbon center
作者:Vellaisamy Sridharan、Lulu Fan、Shinobu Takizawa、Takeyuki Suzuki、Hiroaki Sasai
DOI:10.1039/c3ob41103f
日期:——
The Pd(II)âSDP-catalyzed first enantioselective intramolecular cyclization of α,α-disubstituted γ-alkynoic acids is described. This 5-exo-dig cyclization afforded dihydrofuran-2(3H)-ones bearing a chiral quaternary carbon center in excellent yields with enantioselectivities up to 71%. A mechanism involving palladium(II) species is proposed to rationalize the outcome of the reaction.
介绍了 Pd(II)âSDP 催化的δ,δ-二取代δ-炔酸的首次对映选择性分子内环化。这种 5-exo-dig 环化反应以极好的收率获得了含有手性季碳中心的二氢呋喃-2(3H)-酮,对映选择性高达 71%。提出了一种涉及钯(II)物种的机理,以合理解释反应的结果。