Rhodium-Catalyzed Allylic Substitution with an Acyl Anion Equivalent: Stereospecific Construction of Acyclic Quaternary Carbon Stereogenic Centers
作者:P. Andrew Evans、Samuel Oliver、Jungha Chae
DOI:10.1021/ja306602g
日期:2012.11.28
A highly regio- and stereospecific rhodium-catalyzed allylic alkylation of tertiary allylic alcohol derivatives with a cyanohydrin pronucleophile is described. This direct and operationally simple protocol provides a fundamentally novel approach toward the synthesis of α-quaternary substituted ketones and circumvents many of the inherent problems associated with conventional enolate alkylation reactions
modification in syntheticchemistry but it remains a formidable challenge to perform on unstrained skeletons. Herein, we describe a radical addition-enabled C–C σ-bond cleavage/reconstruction reaction of unstrained allyl ketones to access various functional indanones bearing a benzylic quaternary center. The synthetic utility of this method has been showcased by the first total synthesis of carexane L, an indanone-based
C-C σ 键断裂和重建是合成化学中结构修饰的重要工具,但在无应变骨架上进行仍然是一个巨大的挑战。在此,我们描述了无张力烯丙基酮的自由基加成C-C σ-键裂解/重建反应,以获得带有苄基四元中心的各种功能性茚满酮。该方法的合成实用性已通过茚满酮天然产物 Carexane L 的首次全合成得到展示。