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Studies on Pd 0 ‐Catalyzed Cyclization of N ‐3,4‐Alkadienyl Toluenesulfonamides with Organic Halides: Selective Synthesis of 2,3‐Dihydropyrroles, 1,2,3,6‐Tetrahydropyrridines, and Azetidines
Author(s) -
Ma Shengming,
Yu Fei,
Li Jing,
Gao Wenzhong
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200600431
Subject(s) - halide , catalysis , chemistry , amide , palladium , aryl , medicinal chemistry , organic chemistry , alkyl
The palladium‐catalyzed coupling–cyclization of β‐amino allenes with organic halides ranging from aryl halide to 1‐alkenyl halide was studied. 2,3‐Dihydro‐1 H ‐pyrroles were obtained by reaction of 3‐substituted‐5‐unsubstituted‐3,4‐allenyl amides under conditions A, while the reaction of 5‐substituted‐3,4‐allenyl amides afforded 1,2,5,6‐tetrahydropyridines and/or azetidines with high de under conditions B or C. The skeleton and relative configuration of the six‐membered products were established by the X‐ray diffraction studies of 10 ka . Allenyl amide 4 q reacted with 1,4‐diiodobenzene 6 r to afford double cyclization product 15 . The structure of its major stereoisomer was also determined by the X‐ray diffraction study.