Synthesis 2022; 54(17): 3793-3800
DOI: 10.1055/s-0040-1719879
special topic
Special Issue in memory of Prof. Ferenc Fülöp

Chiral Calcium Phosphate Catalyzed Enantioselective Synthesis of All-Carbon Quaternary Center by Friedel–Crafts Alkylation Reaction of Pyrroles and Trifluoromethylated Nitrostyrenes

,
Sosuke Yokohama
,
Mona Murakami
,
JSPS KAKENHI Grant Numbers JP20H00380 and JP20H04826 (Hybrid Catalysis).


Abstract

A chiral calcium phosphate-catalyzed enantioselective Friedel–Crafts alkylation reaction of pyrroles and α-trifluoromethyl-β-nitrostyrenes has been developed. Pyrroles bearing an all-carbon quaternary center at 2-position were obtained with high to excellent enantioselectivity. Use of 4,7-dihydroindole as a nucleophile and subsequent oxidation resulted in the formation a 2-substituted indole derivative with excellent enantioselectivity. A 3,4-dihydropyrrolo[1,2-c]pyrimidine derivative was successfully synthesized by reduction followed by benzoylation of the product without loss of enantioselectivity. Application to a 1 mmol scale reaction was successfully achieved.

Supporting Information



Publication History

Received: 19 November 2021

Accepted after revision: 13 December 2021

Article published online:
04 February 2022

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