A variety of highly functionalized allenes and allenamides are prepared by intramolecular propargylic ene reactions of benzynes. Specific benzyne precursors having a chlorodiisopropylsilyl group serve as platforms to link with various propargyl alcohols via a Si–O bond, thereby expanding the scope of this reaction. Also demonstrated is a complete transmission of point to axial chirality to give a chiral
Synthesis of the Pyridine Core of Cyclothiazomycin
作者:Yan Zou、Qingyang Liu、Alexander Deiters
DOI:10.1021/ol201682k
日期:2011.8.19
A highly convergent synthesis of the pyridine core of the thiopeptide antibiotic cyclothiazomycin has been developed based on a [2 + 2 + 2] cyclotrimerization key step. The regioselective assembly of the heterocyclic center of this important class of antibiotics takes advantage of a temporary silicon tether and the ruthenium-catalyzed cyclotrimerization reaction of a diyne and an electron-poor thiazole nitrile.