A simple, effective, new, palladium-catalyzed conversion of enol silanes to enones and enals
作者:Richard C. Larock、Timothy R. Hightower、George A. Kraus、Pat Hahn、Deye Zheng
DOI:10.1016/0040-4039(95)00306-w
日期:1995.4
Enol silanes derived from aldehydes and ketones are readily converted to the corresponding α,β-unsaturated carbonyl compounds by 10% Pd(OAc)2 in the presence of one atmosphere of oxygen in DMSO as the solvent.
An efficient and simple source of nitroso reagents and their oxidation reactions are described. The combination of a Lewis acid and a metal nitrite was applied to the oxidation of silyl enol ethers. Amino acid and peptide derivatives were easily accessed through in situ C-C bond cleavage of fully substituted silyl enol ethers upon oxidation.
描述了亚硝基试剂及其氧化反应的有效且简单的来源。路易斯酸和金属亚硝酸盐的组合应用于甲硅烷基烯醇醚的氧化。通过氧化时完全取代的甲硅烷基烯醇醚的原位 CC 键裂解,可以很容易地获得氨基酸和肽衍生物。
Versatile desilylative cross-coupling of silyl enol ethers and allylic silanes via oxovanadium-induced chemoselective one-electron oxidation
作者:Toshikazu Hirao、Takashi Fujii、Yoshiki Ohshiro
DOI:10.1016/s0040-4020(01)81753-1
日期:1994.8
The chemoselective cross-coupling of silylenolethers and allylic silanes to γ,δ-unsaturated ketones is achieved by the oxovanadium (V)-induced oxidative desilylation of the more readily oxidizable organosilicon compounds.
A new selective synthetic method of enol esters (O-acylated products) from silyl enol ether and acid chloride in the presence of CuCl is described. This reaction proceeds smoothly in DMI (1,3-dimethyl-2-imidazolidinone) but not in a less polar solvent. The silicon-copper exchange reaction pathway is proposed for this transformation as in the cases of hydrosilane and alkynylsilane which were previously
A novelcatalyticsystem based on copper(I) and chiral bis(phosphine) dioxides is described. This allows the arylation of silyl enol ethers to access enolizable α-arylated ketones in good yields and enantiomeric excess up to 95%. Noncyclic ketones are amenable substrates with this method, which complements other approaches based on palladium catalysis. Optimization of the ligand structure is accomplished