Auxiliary accelerated reactions: Towards the use of catalytic chiral auxiliaries
摘要:
In competition experiments, the acceleration of reactivity of alkenes tethered to pyridyl groups compared with the corresponding alkenes tethered to phenyl groups in the presence of transition metals was demonstrated for two reaction types: Diels-Alder cycloaddition of enoate esters and catalytic hydrogenation of allylic and homoallylic ethers. The rate accelerations observed are of crucial importance in the development of a new concept for asymmetric catalysis: chiral auxiliaries which can function in a catalytic manner. (C) 1997 Elsevier Science Ltd.
In competition experiments, alkenes tethered to pyridyl groups were found to undergo iridium catalysed hydrogenation more quickly than alkenes tethered to phenyl groups. This is in marked contrast to the results for hydrogenation of some of the individual substrates where alkenes tethered to pyridyl groups were reduced much more slowly than their phenyl counterparts.
The invention relates to the inhibition of histone deacetylase. The invention provides compounds and methods for inhibiting histone deacetylase enzymatic activity. The invention also provides compositions and methods for treating cell proliferative diseases and conditions. One aspect of the invention provides compounds of formula (1):
in which T, A and X are as described herein.
The hydroesterification of alkenes with 2-pyridylmethanol (1) catalyzed by Rh-4(CO)(12) is described. The reaction is accelerated by the presence of a pyridine ring in the alcohol 1. The reaction is applicable to various alkenes, both terminal and internal alkenes.
Solvent-free transesterification in a ball-mill over alumina surface
作者:Tanmay Chatterjee、Debasree Saha、Brindaban C. Ranu
DOI:10.1016/j.tetlet.2012.05.127
日期:2012.8
An efficient procedure for transesterification has been developed in a ball-mill in the absence of any solvent, acid/base or metal catalyst. A variety of methyl, ethyl, allyl esters have been transesterified to higher benzyl and other esters in high yields by this procedure. (C) 2012 Elsevier Ltd. All rights reserved.
Alkylation of Organic Acids with Pyridotriazole<sup>1</sup>