The rhodium-catalyzedasymmetrichydrogenation of various β-dehydroamino acid derivatives to give optically active β-amino acids has been examined. Chiral monodentate 4,5-dihydro-3H-dinaphthophosphepines, which are easily tuned and accessible in a multi-10-g scale, have been used as ligands. The enantioselectivity is largely dependent on the nature of the substituent at the phosphorous atom and on
asymmetric hydrogenation of 13 different β-dehydroaminoacid derivatives to give optically active β-amino acidesters has been examined. Readily accessible monodentate octahydrobinaphthol-based phosphoramidites were used as chiral ligands. Good to excellent enantioselectivities and yields were obtained for the E isomers, whereas poorer catalyst performance was found for the Z isomers. Importantly, to obtain
Novel and Efficient Chiral Bisphosphorus Ligands for Rhodium-Catalyzed Asymmetric Hydrogenation
作者:Wenjun Tang、Andrew G. Capacci、Andre White、Shengli Ma、Sonia Rodriguez、Bo Qu、Jolaine Savoie、Nitinchandra D. Patel、Xudong Wei、Nizar Haddad、Nelu Grinberg、Nathan K. Yee、Dhileepkumar Krishnamurthy、Chris H. Senanayake
DOI:10.1021/ol1000999
日期:2010.3.5
A series of structurally novel, operationally convenient, and efficient chiral 2-phosphino-2,3-dihydrobenzo[d][1,3]oxaphosphole ligands was developed. Applications of ligands 3a and 3b in rhodium-catalyzedasymmetrichydrogenation of α-(acylamino)acrylates and β-(acylamino)acrylates provided excellent enantioselectivities (up to >99% ee) and reactivities (up to 10 000 TON).
开发了一系列结构新颖,操作方便且有效的手性2-膦基-2,3-二氢苯并[ d ] [1,3]氧杂磷配体。配体3a和3b在铑催化的α-(酰基氨基)丙烯酸酯和β-(酰基氨基)丙烯酸酯的不对称氢化反应中的应用提供了极好的对映选择性(高达99%ee)和反应性(高达10000吨)。
Highly Efficient Synthesis of Chiral β-Amino Acid Derivatives via Asymmetric Hydrogenation
作者:Wenjun Tang、Xumu Zhang
DOI:10.1021/ol026935x
日期:2002.11.1
The Rh-TangPhos complex is an efficient hydrogenation catalyst for making chiral beta-amino acid derivatives. With the Rh-TangPhos system, high enantioselectivities (up to 99.6%) and turnover numbers have been obtained in the hydrogenation of E/Z isomeric mixtures of both beta-alkyl and beta-aryl beta-(acylamino)acrylates. [reaction: see text]