A fair exchange: In the title reaction, alkynyllithium serves as an initiator for benzyne generation through an iodine–lithium exchange (see scheme; Tf=trifluoromethanesulfonyl). When performed in the presence of stoichiometric amounts of a nucleophile, the generated benzyne undergoes attack by lithio nucleophiles to generate aryllithium, which is then iodinated by iodoalkyne to give the iodoarenes
Carbocupration−Functionalization of Arynes: Rapid Access to Variably Ortho-Substituted ((<i>E</i>)-3-Phenylprop-1-enyl)silanes
作者:Ashok Ganta、Timothy S. Snowden
DOI:10.1021/ol8021885
日期:2008.11.20
A consecutive three-component coupling reaction involving a lithium di[3-(prop-1-enyltrimethylsilyl)]cuprate, variably substituted ortho-arynes, and a selection of common electrophiles is described. The method affords readily functionalized homobenzylic vinylsilanes with exceptional E-diastereoselectivity and allows for in situ incorporation of carbon- or heteroatom-based electrophiles into the arene.