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
Kinetic resolution of aliphatic acyclic β-hydroxyketones by recombinant whole-cell Baeyer–Villiger monooxygenases—Formation of enantiocomplementary regioisomeric esters
作者:Jessica Rehdorf、Alenka Lengar、Uwe T. Bornscheuer、Marko D. Mihovilovic
DOI:10.1016/j.bmcl.2009.05.014
日期:2009.7
substrates in the enzymatic kinetic and regioselective Baeyer–Villiger oxidation catalyzed by 12 Baeyer–Villigermonooxygenases from different bacterial origin. Excellent enantioselectivities (E >100) could be observed with 4-hydroxy-2-ketones. After acyl migration, the ester undergoes hydrolysis followed by the formation of optically active 1,2-diols. Furthermore, resolution of 5-hydroxy-3-ketones gave
A new method for the preparation of various 1,3-dicarbonyl compounds is described. Oxidation of 3-hydroxycarbonyl compounds without substituent at C-2 position by the Corey-Kim reagent (N-chlorosuccinimide-dimethyl sulfide) afforded the stable dimethylsulfonium methylides, which on reductive desulfurization by zinc-acetic acid furnished the 1,3-dicarbonyl derivatives.On the other hand, the same treatment of 2-mono-, or 2,2-disubstituted 3-hydroxy-carbonyl compounds gave directly the corresponding 1,3-dicarbonyl analogous,respectively.
The first example of aldol reactions between trimethylsilyl enol ethers and aldehydes by the aid of rhodium complex
作者:Susumu Sato、Isamu Matsuda、Yusuke Izumi
DOI:10.1016/s0040-4039(00)85255-7
日期:1986.1
Crossed aldolreaction of trimethylsilyl enol ether with aldehyde is successfully performed with the aid of catalytic amount of rhodium complex, [(COD)Rh(DPPB)]+X− (X = PF6 and ClO4) or Rh4(CO)12, under neutral conditions.
的交叉醛醇缩合反应三甲基硅烯醚与醛可以成功地与铑配合物,[(COD)的Rh(DPPB)]的催化量的帮助下执行+ X -(X = PF 6和C10 4)或Rh 4(CO)12,在中性条件下。
Crossed aldol-type reactions catalyzed by rhodium complexes
作者:Susumu Sato、Isamu Matsuda、Yusuke Izumi
DOI:10.1016/0022-328x(88)83037-7
日期:1988.9
ketones. Rh4(CO)12 and [Rh(COD)(DPPB)]ClO4 also catalyze the reaction of enol trimethylsilyl with acetals or ketals, whereas [Rh(COD)(DPPB)PF6 does not. When [Rh(COD)(DPPB)ClO4 is used as the catalyst, this type of aldol reaction is extended to the one-potsynthesis of trisubstituted furans from enol trimethylsilyl ether and α-trimethylsiloxy acetal.