Efficient Silver-Catalyzed Regio- and Stereospecific Aziridination of Dienes
作者:Josep Llaveria、Álvaro Beltrán、M. Mar Díaz-Requejo、M. Isabel Matheu、Sergio Castillón、Pedro J. Pérez
DOI:10.1002/anie.201003167
日期:2010.9.17
Nitrene transfer: Unsymmetric dienes bearing a terminal hydroxy group can be regio‐ and stereospecifically converted into vinylaziridines upon nitrene transfer from PhINTs using a silver‐based catalyst. Stoichiometric mixtures of dienes and PhINTs were employed at low catalyst loadings (0.5 %; see scheme). The method has been applied to the synthesis of (±)‐sphingosine and gave good yields in a three‐step
between alkenyl- chromium(III) reagents, derived from either (E)-(2-bromoethenyl)benzene or (E)-1-iodo-1-pentadecene, and the conformationally rigid Garner's aldehyde resulted in the stereoselective formation of Felkin-type allylic alcohols in good yields, thus providing an easy access to sphingosines. In addition, when the protecting group in the Garner's aldehyde was changed (from Boc to N-octa- noyl)
A “tunable” stereoselective alkene synthesis by iododesilylation of vinylsilanes
作者:T.H. Chan、K. Koumaglo
DOI:10.1016/s0040-4039(00)84127-1
日期:1986.1
The stereoselectivity of iododesilylation of terminal E-vinylsilanes varies with changing amount of Lewis acid. The use of this “tunable” stereoselective reaction was demonstrated by the syntheses of two insect sex pheromones with defined E/Z isomeric ratios.