钯‐三甲基甲烷和Morita−Baylis−Hillman碳酸盐级联环化双去质子化策略构建双环[3.1.0]己烷框架，这一成果由四川大学华西药学院Ying-Chun Chen小组经过不懈努力而取得。 该研究于2021年4月8日发表于国际一流学术期刊《德国应用化学》。

该研究组报告说，在Morita-Baylis-Hillman碳酸盐存在下，从大量活化的酮，就可以实现Tsuji的2-（氰甲基）烯丙基碳酸酯的化学选择性活化，从而通过去质子化策略生成钯-三亚甲基甲烷1,3-偶极子。

接下来的SN2'加成可以通过第二个去质子化过程形成新的1,3偶极子物种，这些物种具有活化的烯烃部分，然后发生级联[1+2]/[3+2]环化，形成具有三个相邻季系立体中心的复杂双环[3.1.0]己烷框架，具有很好的对映选择性。

此外，通过使用对苯甲酰醛衍生的底物，研究人员类似地开发了[1+4]/[3+2]环化序列，以生产融合的环戊[b]呋喃结构。

附：英文原文

Title: A Double Deprotonation Strategy for Cascade Annulations of Palladium‐Trimethylenemethanes and Morita−Baylis−Hillman Carbonates to Construct Bicyclo[3.1.0]hexane Frameworks

Author: Ying-Chun Chen, Zhen-Hong Yang, Peng Chen, Zhi-Chao Chen, Zhi Chen, Wei Du

Issue&Volume: 2021-04-08

Abstract: Here we report that the chemoselective activation of Tsuji′s 2‐(cyanomethyl) allyl carbonates to generate the palladium‐trimethylenemethane 1,3‐dipoles via a deprotonation strategy can be realized in the presence of Morita-Baylis-Hillman carbonates from substantial activated ketones. The following SN2′‐addition enables the formation of new 1,3‐dipole species having an activated alkene moiety through a second deprotonation process, which then undergo cascade [1+2]/[3+2] annulations to furnish complex bicyclic [3.1.0]hexane frameworks with three contiguous quaternary stereogenic centers with good to excellent enantioselectivity. Moreover, by using benzoyl aldehyde‐derived substrates, a [1+4]/[3+2] annulation sequence is similarly developed to produce fused cyclopenta[b]furan architectures.

DOI: 10.1002/anie.202102842

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202102842