Nilova Aleksandra, Mannchen Michael D, Noel Abdias N, Semenova Evgeniya, Grenning Alexander J
Department of Chemistry, University of Florida PO Box 117200 Gainesville 32611 FL USA
Chem Sci. 2023 Feb 14;14(10):2755-2762. doi: 10.1039/d2sc07021a. eCollection 2023 Mar 8.
An asymmetric allylic alkylation/Cope rearrangement (AAA/[3,3]) capable of stereoselectively constructing vicinal stereocenters has been developed. Strategically integrated 4-methylation on the 3,3-dicyano-1,5-diene controls stereoselectivity and drives Cope rearrangement equilibrium in the forward direction. The AAA/[3,3] sequence rapidly converts abundant achiral and racemic starting materials into valuable (hetero)cycloalkane building blocks bearing significant functional and stereochemical complexity, highlighting the value of (hetero)cyclohexylidenemalononitriles as launching points for complex heterocycle synthesis. On this line, the resulting alkylidenemalononitrile moiety can be readily converted into amides Hayashi-Lear amidation to ultimately yield amido-piperidines, tropanes, and related scaffolds with 3-5 stereocenters and drug-like functionality.
一种能够立体选择性构建邻位立体中心的不对称烯丙基烷基化/Cope重排(AAA/[3,3])反应已被开发出来。策略性地在3,3-二氰基-1,5-二烯上进行4-甲基化可控制立体选择性并驱使Cope重排平衡向正向移动。AAA/[3,3]序列能迅速将大量非手性和外消旋起始原料转化为具有显著官能团和立体化学复杂性的有价值的(杂)环烷烃结构单元,突出了(杂)环己叉基丙二腈作为复杂杂环合成起始点的价值。在此基础上,所得的亚烷基丙二腈部分可通过Hayashi-Lear酰胺化反应轻松转化为酰胺,最终生成具有3至5个立体中心和类药物官能团的氨基哌啶、托烷及相关骨架。