Selective Wacker-type oxidation of terminal alkenes and dienes using the Pd(II)/molybdovanadophosphate (NPMoV)/O2 system
摘要:
Selective Wacker-type oxidation of long-chain terminal alkenes to methylketones was successfully achieved by using Pd(OAC)(2)/molybdovanadophosphate (NPMoV)/O-2 system. The selectivity of the reaction increased by slow addition of the alkenes to the catalytic solution. The oxidation of alpha,omega-dienes was also examined, and the selectivity of the oxidation was found to depend on the chain length of the dienes used. (C) 2002 Elsevier Science Ltd. All rights reserved.
已经开发了分子内 Simmons-Smith (IMSS) 环丙烷化,为构建取代的双环烷烃提供了一种新方法。首先,以高收率制备了含有烯丙醇的功能化的偕二碘烷烃。然后研究了分子内环化形成不同环大小的过程,并证明可以成功合成双环[3.1.0]己烷和双环[4.1.0]庚烷。更大的链长导致含末端烯烃的产物。Analysis of the product distribution for the different ring sizes and under various reaction conditions provided insight into the reactivity of substituted zinc carbenoids, and by the appropriate choice of conditions cyclopropanation could be promoted
Regioselective Alkene Carbon−Carbon Bond Cleavage to Aldehydes and Chemoselective Alcohol Oxidation of Allylic Alcohols with Hydrogen Peroxide Catalyzed by [<i>cis-</i>Ru(II)(dmp)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</sup> (dmp = 2,9-dimethylphenanthroline)
作者:Vladimir Kogan、Miriam M. Quintal、Ronny Neumann
DOI:10.1021/ol052025e
日期:2005.10.1
to the corresponding aldehydes as an alternative to ozonolysis. Secondary alkenes were much less reactive, leading to regioselective oxidation of substrates such as 4-vinylcyclohexene and 7-methyl-1,6-octadiene at the terminal position. Primary allylic alcohols were chemoselectively oxidized to the corresponding allylic aldehydes, e.g., geraniol to citral.
spectrometry show that reaction of I with excess hydrogen peroxide leads to fast formation of a diperoxo species, [TBA](4)[gamma-SiW(10)O(32)(O(2))(2)] (II), with retention of a gamma-Keggin type structure. Whereas the isolated compoundII is inactive for stoichiometric epoxidation of cyclooctene, epoxidation with II does proceed in the presence of hydrogen peroxide. The reaction of II with hydrogen peroxide
Serial Ligand Catalysis: A Highly Selective Allylic C−H Oxidation
作者:Mark S. Chen、Prabagaran Narayanasamy、Nathan A. Labenz、M. Christina White
DOI:10.1021/ja0500198
日期:2005.5.18
We are reporting a mild, chemo-, and highly regioselective Pd(II)-catalyzed allylicoxidation of alpha-olefins to furnish branched allylic esters that proceeds via a novel serial ligand catalysis mechanism in which two different ligands (i.e., vinyl sulfoxide 2 and BQ) interact sequentially with the metal to promote distinct steps of the catalytic cycle (i.e., C-H cleavage and pi-allyl functionalization
The present disclosure relates to unsaturated polyolefins and processes for preparing the same. The present disclosure further relates to curable formulations comprising the unsaturated polyolefins that show improved crosslinking.
Metal-catalyzed organic photoreactions. Chemo- and regioselectivities in the CuCl2-induced photooxidation of olefins
作者:Tadashi Sato、Shin-ichi Yonemochi
DOI:10.1016/s0040-4020(01)90468-5
日期:——
Copper(II) chloride induced the chemo and regioselective chlorohydroperoxidation, as well as the site-selective chlorination of olefins, under photooxygenation conditions.