Enantioselective Friedel-Crafts alkylation of indoles with alkylidene malonates catalyzed by N,N'-dioxide-scandium(III) complexes: asymmetric synthesis of beta-carbolines.
An efficient catalytic asymmetric Friedel-Crafts alkylation of indoles with alkylidene malonates has been developed by using a chiral N,N'-dioxide-Sc(OTf)(3) complex as the catalyst (see scheme). Some optically active intermediates containing the indole skeleton have been synthesized, such as indolepropionic acid, tryptamines, and beta-carbolines. The coordination between the scandium atom and the chiral N,N'-dioxide compound has been revealed by X-ray structure analysis.
Liu
Yanling
Y
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, China.
Shang
Deju
D
Zhou
Xin
X
Liu
Xiaohua
X
Feng
Xiaoming
X
D000478:Alkylation; D002384:Catalysis; D018360:Crystallography, X-Ray; D007211:Indoles / Q000737:chemistry*; D008314:Malonates / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D012538:Scandium / Q000737:chemistry*; D013237:Stereoisomerism
D007211:Indoles; D008314:Malonates; D012538:Scandium