Organocatalytic enantioselective Friedel-Crafts alkylation of 4,7-dihydroindoles with alpha,beta-unsaturated aldehydes: an easy access to 2-substituted indoles.
An enantioselective Friedel-Crafts alkylation of 4,7-dihydroindoles and alpha,beta-unsaturated aldehydes has been developed. The process is promoted by diphenylprolinol ether to afford 2-substituted 4,7-dihydroindoles in high yields and enantioselectivities. After a subsequent oxidation of the products, the optically active 2-substituted indoles could be obtained smoothly in high yields without any loss of enantioselectivity.
Hong
Liang
L
State Key Laboratory of Applied Organic Chemistry and Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou 730000, China.
Liu
Chunxia
C
Sun
Wangsheng
W
Wang
Lei
L
Wong
Kwokyin
K
Wang
Rui
R
D000447:Aldehydes / Q000737:chemistry*; D000478:Alkylation; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D000447:Aldehydes; D007211:Indoles