Metal-Free Catalytic Boration at the β-Position of α,β-Unsaturated Compounds: A Challenging Asymmetric Induction
作者:Amadeu Bonet、Henrik Gulyás、Elena Fernández
DOI:10.1002/anie.201001198
日期:——
Enantiomerically enriched secondary organoboronates containing β‐carbonyl functional groups have been prepared using an unprecedented organocatalytic system (see scheme). The use of chiral tertiary phosphorus compounds induced ee values of up to 95 % in the absence of transition metals.
Processes for preparing beta-hydroxy-ketones and alpha,beta-unsaturated ketones
申请人:Barnicki Donald Scott
公开号:US20050004401A1
公开(公告)日:2005-01-06
Processes for producing β-hydroxy-ketones and α,β-unsaturated ketones are disclosed which comprise the crossed condensation of an aldehyde with a ketone in the presence of a hydroxide or alkoxide of alkali metal or an alkaline earth metal as catalyst. The products of the process, β-hydroxy-ketones and α,β-unsaturated ketones, are useful for the preparation of many commercially important products in the chemical process industries including solvents, drug intermediates, flavors and fragrances, other specialty chemical intermediates.
Au(I)-Catalyzed Cyclization of<i>tert</i>-Butyl Carbonates Derived from Homopropargyl Alcohols: A Catalytic Alternative to Cyclic Enol Carbonates
作者:Seunghoon Shin、Ji-Eun Kang
DOI:10.1055/s-2006-933110
日期:——
Au(I)-complexes catalyze cyclization of tert-butyl carbonates derived from a variety of homopropargyl alcohols. This procedure offers a catalytic alternative to stoichiometric Lewis acids for the preparation of a range of enol carbonates.
Reductive intramolecular cyclization of α-bromo silyl ethers mediated by samarium diiodide
作者:H. S. Park、I. S. Lee、D. W. Kwon、Y. H. Kim
DOI:10.1039/a807736c
日期:——
A new SmI2-promoted intramolecular reductive cyclization of β-(α-bromo siloxy) carbonyl compounds is reported.
报道了一种由SmI2促进的β-(α-溴硅氧基)羰基化合物的分子内还原环化反应。
[EN] A METHOD FOR THE PREPARATION, ISOLATION AND PURIFICATION OF PHARMACEUTICALLY APPLICABLE FORMS OF AHU-377<br/>[FR] PROCÉDÉ DE PRÉPARATION, D'ISOLATION ET DE PURIFICATION DE FORMES PHARMACEUTIQUEMENT APPLICABLES DE AHU-377
申请人:ZENTIVA KS
公开号:WO2016074651A1
公开(公告)日:2016-05-19
An isolation and purification method of substances derived from AHU-377 of formula (1), characterized by conversion of the crude substance (1) to well-crystallizing salts with amines of formula (9) in the environment of a suitable organic solvent, followed by recrystallization of these salts to simultaneously remove chemical impurities, and use of the chemically pure salts of AHU-377 with amines for direct transformation to a pharmaceutically applicable form of AHU-377 with alkali metals of formula (10), or with alkaline earth metals of formula (11).