Highly regio- and stereoselective PdCl2(MeCN)2-catalyzed cross coupling of 1,2-allenylic sulfoxides with allyl bromide
作者:Shengming Ma、Qi Wei、Hongjun Ren
DOI:10.1016/j.tetlet.2004.02.144
日期:2004.4
2-Allyl-1(E),3(E)-dienyl sulfoxides were prepared highlystereoselectively via the PdCl2(MeCN)2-catalyzed coupling reaction of 1,2-allenylicsulfoxides and allyl bromide. A rationale was proposed for this transformation.
It was observed that the halohydroxylation of 1,2-allenyl sulfides or selenides with Br-2 (CuBr2 or NBS) or I-2 and water demonstrated a fairly good regioselectivity (i.e., the C=C bond that is remote from the S or Se atom was halohydroxylated with the halogen atom connecting to the middle carbon atom and the hydroxyl group connecting to the non-S terminal carbon or Se-substituted terminal carbon atom of the allene moiety), leading to the synthesis of synthetically important 3-organosulfur or seleno-2-haloallylic alcohols. The stereoselectivity depends on the nature of X+ and S or Se, showing a Z-selectivity with the matched Lewis acid-base pair.
Studies on highly regio- and stereoselective hydration of 1,2-allenylic sulfoxides
作者:Zhao Fang、Chao Zhou、Chunling Fu、Shengming Ma
DOI:10.1039/c0ob00007h
日期:——
A highlyregio- and stereoselective hydration of 1,2-allenylicsulfoxides in which proton served as the electrophile was reported. Through the X-ray diffraction study, it was concluded that the reaction may proceed via a 5-membered cyclic intermediate following by attack of the −OH at the sulfur atom.