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
presence of a catalytic amount of trityl perchlorate, secondary and tertiary allyl methyl ethers smoothly react with silyl enol ethers to afford the corresponding γ,δ-unsaturated carbonylcompounds in good yields. By the combination of this reaction with the trityl perchlorate catalyzedallylation of acetals γ,δ-unsaturated ketones are synthesized from α,β-unsaturated acetals by a one-pot procedure.
Substitution of allylic alcohols to form a carboncarbonbond is accomplished by a simple reaction of the allylic alcohol itself with an enoxysilane, catalyzed by [Ir(cod)(PPh3)2]X which is activated by H2 molecule. The anion part X of the complexes plays an important role to enhance the rate and product yields of the reactions. The efficacy of the catalyst increases with switching X in the order of
Iridium-catalyzed regioselective decarboxylative allylation of β-ketoacids: efficient construction of γ,δ-unsaturated ketones
作者:Shu-Jie Chen、Guo-Ping Lu、Chun Cai
DOI:10.1039/c5cc03591k
日期:——
A highly regioselective protocol is reported for the efficient construction of γ,δ-unsaturated ketones from β-ketoacids and allylic alcohols.
报道了一种高选择性的方法,用于从β-酮酸和烯丙醇有效构建γ,δ-不饱和酮。
Rhodium-catalyzed substitution of allylic carbonates with enoxysilanes
作者:Takako Muraoka、Isamu Matsuda、Kenji Itoh
DOI:10.1016/s0040-4039(00)01448-9
日期:2000.11
Substitution at the allylic position proceeds smoothly in rhodium-catalyzed reactions of allyl carbonates with enoxysilanes under almost neutral conditions to give gamma,delta -unsaturated ketones in good to excellent yields. (C) 2000 Elsevier Science Ltd. All rights reserved.