The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide
作者:Olga Lifchits、Manuel Mahlau、Corinna M. Reisinger、Anna Lee、Christophe Farès、Iakov Polyak、Gopinadhanpillai Gopakumar、Walter Thiel、Benjamin List
DOI:10.1021/ja402058v
日期:2013.5.1
Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogenperoxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonylcompounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and
METHOD FOR PRODUCING CHIRAL ALPHA,BETA-EPOXY KETONES
申请人:List Benjamin
公开号:US20110009650A1
公开(公告)日:2011-01-13
A process is claimed for the enantioselective epoxidation of α,β-unsaturated ketones, in which a compound of the general formula I,
is reacted with an oxidizing agent to form α,β-epoxy ketones of the general formula II,
in which R
1
, R
2
, R
3
are as defined above. The α,β-epoxy ketones of the general formula II can be obtained in good yields and outstanding enantioselectivities from α,β-unsaturated ketones of the general formula I by epoxidation with hydrogen peroxide in the presence of a chiral catalyst, such as amino compounds and their acid addition salts.
Asymmetric Catalytic Aziridination of Cyclic Enones
作者:Francesco De Vincentiis、Giorgio Bencivenni、Fabio Pesciaioli、Andrea Mazzanti、Giuseppe Bartoli、Patrizia Galzerano、Paolo Melchiorre
DOI:10.1002/asia.201000040
日期:——
The first catalytic method for the asymmetricaziridination of cyclic enones is described. The presented organocatalytic strategy is based on the use of an easily available organocatalyst that is able to convert a wide range of cyclic enones into the desired aziridines with very high enantiomeric purity and good chemical yield. Such a method may very well open up new opportunities to stereoselectively
A new protocol to obtain 3-substituted 2-cyclohexenones, was developed by reversing the chemical reactivity of 2-cyclohexenone. One-pot synthesis of 3-substituted 2-cyclohexenones can be achieved by treatment of 3-phenylthiosilyl enol ether with a mixture of t-BuLi/HMPA that allows hydrogen-selective exchange in presence of reactive electrophiles such as aldehydes, ketones and alkyl halides. This affords