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Et 3 N‐Catalyzed Cycloaddition Reactions of α‐(Trifluoromethyl)styrenes with 2,2, 2‐Trifluorodiazoethane to Access Bis(trifluoromethyl)‐Substituted Pyrazolines
Author(s) -
Li Chunmei,
Zhang Xuxue,
He Jingjing,
Xu Sixue,
Cao Song
Publication year - 2021
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.202000480
Subject(s) - chemistry , trifluoromethyl , cycloaddition , catalysis , substrate (aquarium) , medicinal chemistry , scope (computer science) , combinatorial chemistry , stereochemistry , organic chemistry , oceanography , alkyl , geology , computer science , programming language
Main observation and conclusion A novel and practical method for the synthesis of 3,5‐bis(trifluoromethyl)‐4,5‐dihydro‐1 H ‐pyrazoles by [3+2] cycloaddition reactions of α‐(trifluoromethyl)styrenes with 2,2,2‐trifluorodiazoethane (CF 3 CHN 2 ) has been developed. The cyclization reaction proceeds smoothly in the presence of a catalytic amount of Et 3 N, affording a variety of bis(trifluoromethyl)‐substituted 2‐pyrazolines in good to excellent yields. This method also exhibits a broad substrate scope and tolerates various functional groups.