Concise and Stereoselective Synthesis of Enamides and Dienamides by a Titanium-Mediated Coupling Method
作者:Ryoichi Tanaka、Shuji Hirano、Hirokazu Urabe、Fumie Sato
DOI:10.1021/ol027209x
日期:2003.1.1
Ynamide-titanium alkoxide complexes underwent hydrolysis or addition to aldehydes and ketones to give single, stereodefined di- or trisubstituted enamides in good yields. Alternatively, coupling of a variety of alkyne-titanium alkoxide complexes with terminal ynamides generated amino-substituted titanacyclopentadienes, hydrolysis or aldehyde addition of which afforded stereodefined dienamides.
Practical preparation of N-(1-alkynyl)sulfonamides and their synthetic utility in titanium alkoxide-mediated coupling reactions
olefinic stereo-, and diastereoselective addition to aldehydes to give virtually single allyl alcohols. Alternatively, inter- or intramolecular coupling reaction between N-(1-alkynyl)sulfonamides and another acetylene or olefin with the above titanium alkoxide reagent generated the corresponding titanacycles, hydrolysis of which furnished stereo-defined (sulfonylamino)dienes or cyclic compounds.