西湖大学王兆彬团队报道了醛与卤丙炔的催化对映聚合烯丙化反应。相关研究成果于2022年1月14日发表在国际顶尖学术期刊《德国应用化学》。

α-丙烯醇是有机合成中的一种多功能合成子。从现成的起始材料催化不对称合成α-烯丙醇仍然是一个突出的挑战，特别是当需要同时控制轴向和中心手性时。

该文中，研究人员描述了Cr催化的醛与外消旋炔丙基卤化物的对映聚合烯丙基化反应，以快速获得具有相邻轴向和中心手性的多种手性α-烯丙基醇。该方法具有良好的区域选择性、非对映选择性和对映选择性控制，底物范围广，并且当与Mitsunobu反应结合时，可方便地获得所有四种立体异构体。初步的机理研究支持基于自由基的反应途径。该合成方法在后期功能化和正式全合成(+)-异丙三醇方面的应用证明了其实用性。

附：英文原文

Title: Catalytic Enantioconvergent Allenylation of Aldehydes with Propargyl Halides

Author: Feng-Hua Zhang, Xiaochong Guo, Xianrong Zeng, Zhaobin Wang

Issue&Volume: 2022-01-14

Abstract: α-Allenol is a versatile synthon in organic synthesis. The catalytic asymmetric synthesis of α-allenols from readily available starting materials remains a prominent challenge, especially when simultaneous control over axial and central chirality is required. Herein, we describe the Cr-catalyzed enantioconvergent allenylation of aldehydes with racemic propargyl halides to rapidly access a wide range of chiral α-allenols with adjacent axial and central chiralities. This method features excellent regio-, diastereo- and enantioselectivity control with broad substrate scope, and provides facile access to all four stereoisomers when allied with Mitsunobu reaction. Preliminary mechanistic studies support radical-based reaction pathways. The synthetic utility is demonstrated by the application in late-stage functionalization and the formal total synthesis of (+)-varitriol.

DOI: 10.1002/anie.202117114

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202117114