Enantioselective conjugate addition to cyclic enones with scalemic lithium organo(amido)cuprates, Part IV. Relationship between ligand structure and enantioselectivity
作者:Bryant E. Rossiter、Masakatsu Eguchi、Guobin Miao、Nicole M. Swingle、Amelia E. Hernández、Denise Vickers、Ezdan Fluckiger、R. Greg Patterson、K. Vásavi Reddy
DOI:10.1016/s0040-4020(01)86278-5
日期:1993.1
Scalemic lithium amides derived from primary and secondary amines react with organocopper compounds in ether or dimethyl sulfide to form lithium organo(amido)cuprates capable of enantioselective conjugate addition to 2-cycloalkenones. The most successful heterocuprate, in which the chiral ligand is (S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine, (S)-MAPP, 13, reacts with cyclic enones to form products
Organocopper(I) reagents, RCu, are both more stable and more reactive when prepared in dimethyl sulfide instead of ether or tetrahydrofuran. A wide range of Li reagents has been investigated with good results, as has a selection of Grignard reagents. Excellent yields of products are observed with typical substrates such as α,β-unsaturated ketones and acid chlorides.
Gas-phase reactions of iron(1+) with ketones and ethers
作者:R. C. Burnier、G. D. Byrd、B. S. Freiser
DOI:10.1021/ja00405a012
日期:1981.7
A pulsed laser has been used in conjunction with an ioncyclotronresonance spectrometer to generate and study the gas-phase ion-molecule reactions of Fe/sup +/ with simple carbonyl compounds and ethers. Oxidative addition reactions are observed, producing alkyl acyl, and alkoxide intermediates which undergo intramolecular rearrangement by a ..beta..-hydride shift mechanism. Decarbonylation reactions
Three different electrochemical methods have been applied for the synthesis of chiral building blocks for diastereoselective amidoalkylation reactions. These are A. the direct anodic α-methoxylation of amides and carbamates; B. anodic methoxylative decarboxylation of α-amino acid derivatives (Hofer-Moest reaction) C. indirect NaCl mediated anodic α-methoxylation of α-amino acid derivatives. The application of these building blocks for the synthesis of enantiomerically pure α-amino acids, dichiral 1,2-amino alcohols and chiral 1,3-diamines is described.
Sulfoxide-Controlled S<sub>N</sub>2‘ Displacements between Cyanocuprates and Epoxy Vinyl Sulfoxides<sup>1</sup>
作者:Joseph P. Marino、Laura J. Anna、Roberto Fernández de la Pradilla、María Victoria Martínez、Carlos Montero、Alma Viso
DOI:10.1021/jo000468k
日期:2000.10.1
Two short and convergentroutes have been devised for the preparation of enantiomerically pure acyclic epoxy vinyl sulfoxides. These substrates undergo highly regio- and stereoselective S(N)2' displacements with lithium cyanocuprates to give alpha'-alkylated, gamma-oxygenated Z alpha,beta-unsaturated sulfoxides in moderate to good yields and with good to excellent diastereoselectivities. The absolute