通过使用副念珠菌ATCC 7330的全细胞进行消旋,获得了各种具有芳烃和烷基取代基的光学纯炔丙醇,具有优异的ee(最高> 99%)和分离的收率(最高87%)。整个细胞显示出对烷基取代的底物特异性随着链长的增加,已观察到炔丙醇和对映选择性的变化,从“ R ”变为“ S ”。对映体纯(R)-4-(3-羟基丁-1-炔基)苄腈,(R)-4-(联苯-4-基)丁-3-炔-2-醇,(S)- 3-羟基-5-苯基戊-4-酸乙酯和(S使用该策略获得了)-4-苯基丁-3-炔-1,2-二醇。如此获得的光学纯的炔丙醇用作手性起始原料,成功合成了对映体富集的多取代的吡咯烷和吡咯衍生物,成功地证明了化学酶促路线。
new chiral β-hydroxy amide ligands were synthesized via the reaction of benzyl chloride and aminoalcohols derived from l-tyrosine. The titanium(IV) complex of chiral ligand 8b was found to be an effective catalyst for the asymmetric alkynylation of aliphatic, vinyl and aromatic aldehydes. The propargyl alcohols were obtained in highly enantiomeric excesses (up to 96% ee) under optimized conditions.
Highly Enantioselective Addition of Phenylacetylene to Aldehydes Catalyzed by a Camphorsulfonamide Ligand
作者:Zhaoqing Xu、Chao Chen、Jiangke Xu、Mingbo Miao、Wenjin Yan、Rui Wang
DOI:10.1021/ol036418u
日期:2004.4.1
The asymmetricaddition of phenylacetylene to aldehydes was carried out by using a camphorsulfonamide titanium complex as a catalyst. The reactions proceeded under mild conditions and gave the products with good yields and high ees. This system is very useful for the synthesis of chiral propargylic alcohol. [reaction: see text]
Asymmetric Addition of Phenylacetylene to Aldehydes Catalyzed by β-Sulfonamide Alcohol-Titanium Complex
作者:Zhaoqing Xu、Li Lin、Jiangke Xu、Wenjin Yan、Rui Wang
DOI:10.1002/adsc.200505453
日期:2006.3
A series of β-sulfonamide alcohol ligands were synthesized from L-phenylalanine. Titanium complexes of these compounds were used to catalyze the asymmetricaddition of phenylacetylene to a number of aldehydes. When the conditions were optimized, 20 mol % of ligand 8a catalyzed the reaction with high enantioselectivity (up to 98% ee) and good yield (up to 92%). When a small amount of MeOH was added
A Concise Synthesis of (S)-(+)-Ginnol Based on Catalytic Enantioselective Addition of Commercially Unavailable Di(n-alkyl)zinc to Aldehydes and Ketones
作者:Kazuaki Ishihara、Manabu Hatano、Tomokazu Mizuno
DOI:10.1055/s-0030-1258129
日期:2010.8
Catalytic, enantioselective n-alkyl addition of commercially unavailable di(n-alkyl)zinc reagents, which were prepared by a refined version of Charette's procedure with Grignard reagents, to aldehydes and ketones was developed. To minimize the side reactions in the catalysis by chiral phosphoramide ligand (1) or 3,3'-diphosphoryl-BINOL ligand (2), a preparation of di(n-alkyl)zinc reagents with a 1:2
A series of polymer‐supported chiral β‐hydroxy amides and C2‐symmetric β‐hydroxy amides have been synthesized and successfully used for the enantioselective addition of phenylacetylene to aldehydes. High yields (up to 93%) and enantioselectivities (up to 92% ee) were achieved by using polymer‐supported chiral β‐hydroxy amide 4b. The resin 4b is reused four times, giving the product with enantioselectivity