Access to Functionalized Quaternary Stereocenters via the Copper-Catalyzed Conjugate Addition of Monoorganozinc Bromide Reagents Enabled by <i>N</i>,<i>N-</i>Dimethylacetamide
作者:Tyler J. Fulton、Phebe L. Alley、Heather R. Rensch、Adriana M. Ackerman、Cameron B. Berlin、Michael R. Krout
DOI:10.1021/acs.joc.8b02201
日期:2018.12.7
reagents, readily obtained from alkyl bromides, display excellent reactivity with β,β-disubstituted enones and TMSCl in the presence of Cu(I) and Cu(II) salts to synthesize a variety of cyclic functionalized β-quaternary ketones in 38–99% yields and 9:1–20:1 diastereoselectivities. The conjugate addition features a pronounced improvement in DMA using monoorganozinc bromide reagents. A simple one-pot protocol
A directing effect of neighboring aromatic groups on the regiochemistry of formation and stereochemistry of alkylation and bromination of ketone lithium enolates. Evidence for lithium-arene coordination and dramatic effect of copper(I) in controlling stereochemistry and limiting polyalkylation