An efficient double catalytic system, combining chiral amine and 2-mercaptobenzoic acid, is applied for α′,β-regioselective [4+2] annulations of 2-cyclopentenone with a diversity of activated alkenes, constructing multifunctional chiral bicycle[2,2,1]heptane scaffolds in good to excellent yields and enantioselectivities. In comparison with the traditional cross-dienamine species between 2-cyclopentenone and chiral amine, the interrupted enamine intermediate containing a covalently linked thiol catalyst shows significantly improved reactivity.

中文翻译：

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不对称[4 + 2]环空通过双胺-硫醇催化与2-环戊烯酮一起构建正樟脑支架

一种高效的双催化体系，将手性胺和2-巯基苯甲酸结合在一起，用于2-环戊烯酮与多种活化烯烃的α'，β-区域选择性[4 + 2]环化反应，构建了多功能手性自行车[2,2， 1]庚烷支架具有良好至极好的收率和对映选择性。与2-环戊烯酮和手性胺之间的传统交叉二烯胺相比，含有共价连接的硫醇催化剂的间断烯胺中间体显示出显着改善的反应性。