A Catalytic Strategy for α,ω‐Functionalization: NHC‐Mediated Fragmentation/Umpolung Cascades to Access Hydroxytrifluoromethyl Ynones and Allenones
作者:Christoph Selg、Fabian B. Kraft、Linda Welcke、Kirsten Zeitler
DOI:10.1002/cctc.201801454
日期:2019.8.21
aldehydes are subsequently trapped by NHC‐catalyzed umpolung and further metal‐free C−C‐cross‐coupling to access a broad scope of terminally modified alkynyl or allenyl aliphatic, aromatic and heteroaromatic trifluoromethyl ketones as multifunctionalized, high‐value building blocks for advanced synthetic applications. Additional synthetic utility of this approach is demonstrated with the possibility
在本文中,我们报道了前所未有的,便捷的NHC催化一锅级联反应,可在单个步骤中提供α,ω-双官能化的羟基三氟甲基炔烃和烯丙二酮。关键的易碎脂族醛是通过碱介导的原位引入的相应的潜在环状三氟乙缩醛三氟甲磺酸盐(VHAT)和γ-羟基乙烯基三氟甲磺酸盐(GHVT)前体的Grob型裂解,避免了典型的问题和分离时的损失。随后,“脱掩模的”醛被NHC催化的聚苯乙烯和其他无金属的C-C交叉偶联捕获,从而获得了广泛的末端修饰的炔基或烯丙基脂族,芳族和杂芳族三氟甲基酮,作为多功能化,高价值的建筑适用于高级合成应用的模块。使用手性NHC催化剂可能会产生不对称变体,从而证明了该方法的其他合成效用。