Asymmetric 1,4-Addition of Diethylzinc to Cyclic Enones Catalyzed by Cu(I)-Chiral Sulfonamide-Thiophosphoramide Ligands and Lithium Salts
作者:Min Shi、Wen Zhang
DOI:10.1002/adsc.200404321
日期:2005.3
The chiral sulfonamide-thiophosphoramideligand L1, prepared from the reaction of (1R,2R)-(−)-1,2-cyclohexanediamine with diphenylthiophosphoryl chloride and p-toluenesulfonyl chloride, was used as a chiral ligand in Cu(MeCN)4ClO4-promoted catalytic asymmetric addition of diethylzinc to cyclicenones using LiCl as an additive in which up to 90% ee can be realized under mild conditions within 0.5 h
由(1 R,2 R)-(-)-1,2-环己二胺与二苯基硫代磷酰氯和对甲苯磺酰氯反应制得的手性磺酰胺-硫代磷酰胺配体L1用作Cu(MeCN)中的手性配体使用LiCl作为添加剂的4 ClO 4促进的二乙基锌向环烯酮的催化不对称加成反应,在温和的条件下,在0.5小时内可实现高达90%ee。该手性配体在常规处理后稳定且可回收,并且可以在相同的催化不对称反应中重复使用。此外,发现基于1 H NMR,该系列手性配体代表一种S,O-双齿配体。31 P NMR和13 C NMR光谱研究。配体ee和产物ee的线性效应进一步表明,活性物质是带有单个配体的单体Cu(I)配合物。
Chiral C1-symmetric diaminothiophosphoramide–Cu(I) catalyzed asymmetric addition of diethylzinc to N-sulfonylimines
作者:Min Shi、Wen Zhang
DOI:10.1016/j.tetasy.2003.09.031
日期:2003.10
In the presence of a catalytic amount of chiral diaminothiophosphoramide L7 (6 mol%) and Cu(I) (3 mol%), the asymmetric addition of diethylzinc to N-sulfonylimines could be achieved in good yields with moderate to good e.e. (50-74% e.e.) at 0degreesC in toluene. A novel chiral diaminothiophosphoramide ligand system for this asymmetric addition reaction has been explored. (C) 2003 Elsevier Ltd. All rights reserved.
Highly Enantioselective Michael Addition of Acetone to Nitro Olefins Catalyzed by Chiral Bifunctional Primary Amine-Thiophosphoramide Catalyst
A series of bifunctional primary amine-thiophosphoramides were synthesized, which proven to be effective organocatalysts for the asymmetric Michael reaction of acetone to both aryl and alkyl nitro olefins in the presence of phenol as a protic additive. The corresponding adducts were obtained in excellent chemical yields (up to >99 %) with excellent enantioselectivities (up to 97 % ee).
Asymmetric 1,4-addition of diethylzinc to α,β-unsaturated enones catalyzed by chiral imino-thiophosphoramide ligands and copper(I)
作者:Min Shi、Wen Zhang
DOI:10.1016/j.tetasy.2003.11.015
日期:2004.1
a catalytic amount of chiral imino-thiophosphoramide ligand L7 (6 mol %) and Cu(I) salt (3 mol %), the asymmetric addition of diethylzinc to α,β-unsaturated carbonyl compounds could be achieved in good yields with moderate ees (up to 75% ee) at −20 °C in toluene. A novel chiral imino-thiophosphoramide ligand system for this asymmetric1,4-addition reaction has been explored.