The methanolysis of allylicalcohols, benzylic tertiary alcohols and epoxides in the presence of a catalytic amount of cericammoniumnitrate (CAN) is shown to be catalysed by protons generated from the oxidation of methanol. This reaction is also catalysed by Lewis acids.
Molybdenum(II)- and Tungsten(II)-Catalyzed Allylic Substitution
作者:Andrei V. Malkov、Ian R. Baxendale、Dalimil Dvořák、Darren J. Mansfield、Pavel Kočovský
DOI:10.1021/jo9821776
日期:1999.4.1
The molybdenum(II) complexes Mo(CO)(5)(OTf)(2) (7a), [Mo(CO)(4)Br(2)](2) (8a), their tungsten(II) congeners 7b and 8b, and bimetallic complex Mo(CO)(3)(MeCN)(2)(SnCl(3))Cl (9a) have been found to catalyze the C-C bond-forming allylic substitution with silyl enol ethers derived from beta-dicarbonyls (e.g., 16 + 30 --> 46) or from simple ketones (e.g., 16 + 32 --> 50), aldehydes, and esters as nucleophiles
Mild Two-Step Process for the Transition-Metal-Free Synthesis of Carbon−Carbon Bonds from Allylic Alcohols/Ethers and Grignard Reagents
作者:Xinping Han、Yanhua Zhang、Jimmy Wu
DOI:10.1021/ja100747n
日期:2010.3.31
A mild two-step process for the regioselective, transition-metal-free preparation of carbon-carbon bonds from allylic alcohols/ethers and Grignardreagents is described. This process obviates the need for the harsh deprotection conditions usually required for removal of methyl ethers. The synthesis is accomplished by photochemically promoted allylic substitution reactions of allylic alcohols and ethers
The reaction of allylic alcohols in benzene–methanol (3 : 2) solvent in the presence of cis-dichlorobis(triphenylphosphine)platinum(II)–tin(II) chloride dihydrate complex catalyst afforded allylic methyl ethers. The structure of the obtained compounds was identified by direct comparison with authentic sample. Cholest-4-en-3α-ol, with a quasi-axial hydroxy group, gave a quantitative yield of 3α-methoxycholest-4-ene
Conversion of conjugated p-tosylhydrazones to the corresponding ethers by sodium borohydride, sodium alkoxide, or potassium carbonate in alcohol solvents
作者:Romano Grandi、Alessandro Marchesini、Ugo M. Pagnoni、Roberto Trave