N-Heterocyclic carbene (NHC) catalyzed regiospecific β-additions of nitrogen-containing nucleophiles including nitrogenous heterocycles and trifluoromethylated acylhydrazone to allenoates were accomplished under mild reaction conditions, harnessing NHC as a Lewis base to furnish branched N-alkyl compounds in moderate to good yields with high E/Z selectivity and broad substrate scope. DFT calculations on the possible reaction mechanisms show that the β-addition pathway is more energetically favourable than the γ-addition pathway, which is in agreement with the experimental observations.

中文翻译：

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NHC催化的N基亲核试剂的β特异性加成物

在温和的反应条件下，完成了N-杂环卡宾（NHC）催化的含氮亲核试剂（包括含氮杂环和三氟甲基化酰hydr）的区域特异性β加成反应，从而利用NHC作为Lewis碱，以中等至良好的收率提供了支链N-烷基化合物具有较高的E / Z选择性和广泛的底物范围。对可能的反应机理的DFT计算表明，β-添加途径比γ-添加途径在能量上更有利，这与实验观察结果一致。