Development of a New Class of Chiral Phosphorus Ligands: P-Chirogenic Diaminophosphine Oxides. A Unique Source of Enantioselection in Pd-Catalyzed Asymmetric Construction of Quaternary Carbons
phosphorus compounds have been successfully applied to Pd-catalyzed asymmetric construction of tertiary and quaternary carbons. The actual ligand structure was the trivalent phosphorus species 17, which was generated in situ by BSA-induced P(V) to P(III) transformation of 6, the preligand. Detailed mechanistic studies, including asymmetric amplification and initial rate kinetics, revealed that complex 18
Catalyst dependent mechanistic paths in the reactions of ethyl diazoacetate with β-keto esters
作者:Andrew C. Lottes、John A. Landgrebe、Kristin Larsen
DOI:10.1016/s0040-4039(00)99330-4
日期:1989.1
The catalyzed decomposition of ethyldiazoacetate in the presence of β-keto esters produces regioisomeric enol ethers and the diester from formal carbenoid insertion into the α-C-H bond. The product distribution is very catalyst dependent.
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。
Synthesis and Reactivity of β-Methoxymethyl Enecarbamates
作者:Patrick D. O’Connor、Michael G. Marino、Stéphanie M. Guéret、Margaret A. Brimble
DOI:10.1021/jo901992z
日期:2009.11.20
beta-Methoxymethyl enecarbamates (e.g., 1) have been prepared in a single step from alpha-methoxy carbamates. In the presence of a mild Lewis acid, compound I underwent substitution with a variety of nucleophiles including indoles, electron-rich aromatics, silyl enol ethers, and 2-trimethylsinlyloxyfuran.