Improved Conditions for the Proline-Catalyzed Aldol Reaction of Acetone with Aliphatic Aldehydes
作者:Benjamin List、Alberto Martínez、Kristina Zumbansen、Arno Döhring、Manuel van Gemmeren
DOI:10.1055/s-0033-1340919
日期:——
The proline-catalyzed asymmetric aldol reaction between aliphatic aldehydes and acetone has, to date, remained underdeveloped. Challenges in controlling this reaction include avoiding undesired side reactions such as aldol condensation and self-aldolization. In recent years we have developed optimized conditions, which enable high yields and good to excellent enantioselectivities, and which are presented
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.
Direct organocatalytic aldol reactions in buffered aqueous media
作者:Armando Córdova、Wolfgang Notz、Carlos F. Barbas III
DOI:10.1039/b207664k
日期:——
Organocatalytic cross-aldol reactions catalyzed by cyclic secondary amines in aqueous media provide a direct route to a variety of aldols including carbohydrate derivatives and may warrant consideration as a prebiotic route to sugars.
Influence of the Double-Bond Geometry of the Michael Acceptor on Copper-Catalyzed Asymmetric Conjugate Addition
作者:Magali Vuagnoux-d'Augustin、Alexandre Alexakis
DOI:10.1002/ejoc.200700424
日期:2007.12
aspects, a study of the influence of the (E)/(Z) double-bond geometry of the Michael acceptor on the enantioselectivity of copper-catalyzedasymmetricconjugateaddition reactions has been realized. In spite of numerous articles concerning copper-catalyzedasymmetricconjugateaddition reactions, the major factors of such a reaction are quite difficult to elucidate. Although our experiments have not allowed
Directed methallylations as a synthetic route to 1,3-polyols
作者:Linda Joy Brzezinski、James W. Leahy
DOI:10.1016/s0040-4039(98)00182-8
日期:1998.4
The directed methallylation of β-hydroxyaldehydes and ketones with methallyboronic acid is examined. The reaction proceeds with good to excellent selectivity with ketones.