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Halogen Bond‐Catalyzed Povarov Reactions
Author(s) -
Liu Xuelei,
Toy Patrick H.
Publication year - 2020
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.202000665
Subject(s) - chemistry , catalysis , halogen , halogen bond , organic chemistry , polymer chemistry , combinatorial chemistry , alkyl
Abstract The use of a bidentate halogen bond donor to catalyse Povarov reactions of imines derived from aryl adehydes and anilines is reported. Dienophiles used in these reactions included 2,3‐dihydrofuran, N ‐vinyl‐2‐pyrrolidone and N ‐Cbz‐protected 2,3‐dihydropyrrole. Very high isolated yields of the desired 1,2,3,4‐tetrahydroquinoline products were obtained with low catalyst loadings (0.01 equivalents) and short reaction times (minutes to hours) at ambient temperature. Notably, the bis(benzimidazolium iodide)‐based catalyst used in these reactions proved to be more efficient than analogous bromine and chlorine functionalized compounds, as well as a related monodentate benzimidizolium iodide. These observations are similar to what has been reported by others regarding halogen bond organocatalysis, and may prove useful in guiding catalyst design as the field moves forward.