Efficient synthesis of beta-hydroxy-alpha-amino acid derivatives via direct catalytic asymmetric aldol reaction of alpha-isothiocyanato imide with aldehydes.
An easily available and efficient chiral N,N'-dioxide-nickel(II) complex catalyst has been developed for the direct catalytic asymmetric aldol reaction of alpha-isothiocyanato imide with aldehydes which produces the products in morderate to high yields (up to 98 %) with excellent diastereo- (up to >99:1 d.r.) and enantioselectivities (up to >99 % ee). A variety of aromatic, heteroaromatic, alpha,beta-unsaturated, and aliphatic aldehydes were found to be suitable substrates in the presence of 2.5 mol % L-proline-derived N,N'-dioxide L5-nickel(II) complex. This process was air-tolerant and easily manipulated with available reagents. Based on experimental investigations, a possible transition state has been proposed to explain the origin of reactivity and asymmetric inductivity.
Chen
Xiaohong
X
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
Zhu
Yin
Y
Qiao
Zhen
Z
Xie
Mingsheng
M
Lin
Lili
L
Liu
Xiaohua
X
Feng
Xiaoming
X
D000447:Aldehydes / Q000737:chemistry*; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D007094:Imides / Q000737:chemistry*; D017879:Isothiocyanates / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry; D009589:Nitrogen Oxides / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D000596:Amino Acids; D007094:Imides; D017879:Isothiocyanates; D009589:Nitrogen Oxides; D009942:Organometallic Compounds; D009532:Nickel