[EN] TRANSITION METAL CARBENE COMPLEXES CONTAINING A CATIONIC SUBSTITUENT AS CATALYSTS OF OLEFIN METATHESIS REACTIONS<br/>[FR] COMPLEXES CARBENES DE METAUX DE TRANSITION CONTENANT UN SUBSTITUANT CATIONIQUE, UTILISES EN TANT QUE CATALYSEURS DES REACTIONS DE METATHESE DES OLEFINES
申请人:UNIV TECHNOLOGIES INT
公开号:WO2005121158A1
公开(公告)日:2005-12-22
Organometallic complexes suitable as olefin metathesis catalysts are provided. The complexes are Group 8 transition metal carbenes bearing a cationic substituent and having the general structure (I) wherein M is a Group 8 transition metal, L1 and L2 are neutral electron donor ligands, X1 and X2 are anionic ligands, m is zero or 1, n is zero or 1, and R1,W, Y, and Z are as defined herein. Methods for synthesizing the complexes are also provided, as are methods for using the complexes as olefin metathesis catalysts.
Synthesis of 3-bromo-2-pyrones and their reactions with bases
作者:T. L. Gilchrist、C. W. Rees
DOI:10.1039/j39680000769
日期:——
The synthesis of α-pyrones related to isodehydracetic acid (2,4-dimethyl-6-oxopyran-3-carboxylic acid), their bromination, and the reaction of the bromo-compounds with bases have been reinvestigated and extended. The sodium-catalysed condensation of β-keto-esters and related compounds with acetyenic esters provides a satisfactory general method for synthesis of the α-pyrones. The reactions of the bromo-pyrones
Racemic Feist's acid is treated with (R)-(+) -.alpha.-methylbenzylamine to yield (1R-trans)-3-methylene -cyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzyl-amine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.
Process and intermediates for the preparation of an antiviral agent containing a cyclobutyl group
申请人:E.R. SQUIBB & SONS, INC.
公开号:EP0535448A2
公开(公告)日:1993-04-07
Racemic Feist's acid is treated with (R)-(+)-a-methylbenzylamine to yield (1R-trans)-3-methylenecyclopropane-1,2-dicarboxylic acid, (R)-a-methylbenzylamine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent Ä1R-(1a,2b,3a)Ü-2-amino-9-Ä2,3-bis(hydroxymethyl)cyclobutylÜ-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.