Lipase-mediated diastereoselective and enantioselective acetylations of 3-substituted cyclohexanols
摘要:
Lipase-mediated acetylation of four diastereomeric and enatiomeric isomers of 3-substituted cyclohexanols 2 has led to an efficient resolution to provide a single stereoisomer, (1R,3S)-cyclohexyl acetate (1R,3S)-3 in a high enantiomeric excess. (C) 1998 Elsevier Science Ltd. All rights reserved.
Enantioselective conjugate addition to cyclic enones with scalemic lithium organo(amido)cuprates, Part IV. Relationship between ligand structure and enantioselectivity
作者:Bryant E. Rossiter、Masakatsu Eguchi、Guobin Miao、Nicole M. Swingle、Amelia E. Hernández、Denise Vickers、Ezdan Fluckiger、R. Greg Patterson、K. Vásavi Reddy
DOI:10.1016/s0040-4020(01)86278-5
日期:1993.1
Scalemic lithium amides derived from primary and secondary amines react with organocopper compounds in ether or dimethyl sulfide to form lithium organo(amido)cuprates capable of enantioselective conjugate addition to 2-cycloalkenones. The most successful heterocuprate, in which the chiral ligand is (S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine, (S)-MAPP, 13, reacts with cyclic enones to form products
Mixed Organocuprates Derived from ortho-Heterosubstituted ArCu Species. Reactions with Simple α,β-Unsaturated Ketones
作者:F. Arevalo、L. Castedo、B. R. Fernandez、A. Mouriño、L. Sarandeses
DOI:10.1246/cl.1988.745
日期:1988.5.5
We describe the reaction of new organocuprates of the form ArRTCuLi (Ar an ortho-heterosubstituted non-transferable ligand), and their reactions with simple α,β-unsaturated ketones.
Organocopper(I) reagents, RCu, are both more stable and more reactive when prepared in dimethyl sulfide instead of ether or tetrahydrofuran. A wide range of Li reagents has been investigated with good results, as has a selection of Grignard reagents. Excellent yields of products are observed with typical substrates such as α,β-unsaturated ketones and acid chlorides.
2-Acyl-3-substituted cyclopentan-1-ones and process for their preparation
申请人:Teijin Limited
公开号:US04009196A1
公开(公告)日:1977-02-22
1,3-Dicarbonyl compounds useful as medicines, agricultural chemicals, perfumes, and their intermediates are prepared by reacting a specific .alpha.,.beta.-unsaturated carbonyl compound with a specific organic copper lithium compound in the presence of an aprotic inert organic solvent, and then reacting the reaction product with an organic carboxylic acid halide or anhydride. In particular, novel 2-acyl-3-substituted cyclopentan-1-ones and 2-acyl-3-substituted cyclohexan-1-ones having important physiological activities are provided.
Copper-catalyzed reactions of organotitanium reagents. Highly selective SN2′-allylation and conjugate addition
作者:Masayuki Arai、Bruce H. Lipshutz、Eiichi Nakamura
DOI:10.1016/0040-4020(92)80022-8
日期:1992.7
the presence of a catalytic amount of CuI·2LiCl, alkyltitanium (RTi(O-i-Pr)3) and titanate reagents (RnTi(O-i-Pr)5−nLi) undergo highlyselectiveSN2′-alkylation reactions with allylic chlorides and allylic diethylphosphates in high yields. The regioselectivity of the reaction is as high as 99.8%. The reaction proceeds with excellent anti-stereoselectivity with respect to the nucleophile and the leaving
在催化量的CuI·2LiCl存在下,烷基钛(RTi(Oi-Pr)3)和钛酸酯试剂(R n Ti(Oi-Pr)5−n Li)进行高度选择性的S N 2'-烷基化反应,烯丙基氯化物和烯丙基磷酸二乙酯的收率很高。反应的区域选择性高达99.8%。反应的进行具有优异的抗-stereoselectivity相对于亲核试剂和离去基团,表现出高的1,2-反-diastereoselectivity与δ手性烯丙基氯。催化铜试剂还是在Me 3存在下将烷基转移至烯酮的缓和剂氯化硅。烷基钛基催化试剂选择性地与烯丙基磷酸盐而不是与烯酮反应,而在硅活化剂的存在下,它优先与烯酮而不是与磷酸盐反应。Me 2 CuLi和TiCl(Oi-Pr)3的混合物的1 H NMR研究提供了有关试剂组成的信息。