Arylthio-Metal Exchange of α-Arylthioalkanenitriles
摘要:
The addition of BuLi, Bu3MgLi, Et2ZnBuLi, or Me2CuLi to alpha-arylthioalkanenitriles triggers an arylthio-metal exchange. NMR spectroscopic analyses implicate organometallic attack on sulfur forming a three-coordinate sulfidate as the key intermediate. Electrophilic trapping affords tertiary and quaternary nitriles in high yield. The method addresses the challenge of improving the functional group tolerance and preventing polyalkylations.
Nitrile Alkylations through Sulfinyl-Metal Exchange
作者:Dinesh Nath、Fraser F. Fleming
DOI:10.1002/anie.201105630
日期:2011.12.2
Triple alkylation: Phenylsulfinyl‐ and phenylthioacetonitrile can function as trianion equivalents of acetonitrile by sequential alkylation and sulfinyl–metal exchange (see scheme; mCPBA=meta‐chloroperoxybenzoic acid). The metalated nitriles alkylate a range of electrophiles to obtain nitriles with quaternary centers. The sulfinyl–metal exchange proceeds under very mild conditions and has a high functional‐group
organolithiums, Grignardreagents, or zincates to sulfinylnitriles triggers a facile sulfinyl–metal exchange to afford N‐ or C‐metalated nitriles. Sulfinyl–magnesium exchange–alkylations efficiently install quaternary and tertiary centers, even in the case of tertiary sulfinylnitriles that contain a highly acidic methine proton. α‐Sulfinylalkenenitriles afford moderately nucleophilic magnesiated nitriles, and
A highly efficient catalyst for Pd-catalyzed cyclopropanation was developed using a bulkier N-heterocyclic carbene ligand, with which the nitriles reacted with mono substitutedallyl reagents to afford cyclopropanes in high yields with high cyclopropanation/allylation and enantioselectivities. The reasons for cyclopropanation were investigated and the usefulness of the products was demonstrated.
Arylthio-Metal Exchange of α-Arylthioalkanenitriles
作者:Dinesh Nath、Melanie C. Skilbeck、Iain Coldham、Fraser F. Fleming
DOI:10.1021/ol403020s
日期:2014.1.3
The addition of BuLi, Bu3MgLi, Et2ZnBuLi, or Me2CuLi to alpha-arylthioalkanenitriles triggers an arylthio-metal exchange. NMR spectroscopic analyses implicate organometallic attack on sulfur forming a three-coordinate sulfidate as the key intermediate. Electrophilic trapping affords tertiary and quaternary nitriles in high yield. The method addresses the challenge of improving the functional group tolerance and preventing polyalkylations.