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Intramolecular Bromoamination of Conjugated N ‐Tosylaminodienes Using N ‐Bromosuccinimide. Synthesis of Bromoallyl‐Substituted N ‐Heterocycles and Their Applications as Building Blocks
Author(s) -
MárquezSegovia Isabel,
Baeza Alejandro,
Otero Antonio,
Nájera Carmen
Publication year - 2013
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201300444
Subject(s) - chemistry , n bromosuccinimide , intramolecular force , moiety , allylic rearrangement , medicinal chemistry , nucleophile , azide , olefin fiber , reductive elimination , bromine , cyanide , vinyl bromide , halogenation , palladium , bromide , conjugated system , suzuki reaction , organic chemistry , catalysis , polymer
The bromonium‐promoted cyclization of conjugated aminodienes is described. The reaction proceeds smoothly in the presence of N ‐bromosuccinimide as halonium promoter, and using N ‐tosyl‐protected aminodienes as substrates, to give the corresponding halocyclization products in high yields and with high diastereoselectivities. It can be envisaged that the formation of these products is the result of an S N 2′‐type ring‐opening of a terminal bromonium intermediate in a 5‐ exo ‐ trig or 6‐ exo ‐ trig cyclization mode. The presence of an allyl bromide moiety in the haloamination products makes these molecules highly attractive from a synthetic point of view, as it opens the way for further transformations. Thus, allylic substitution reactions with different nucleophiles (acetate, azide, cyanide, and malonate), palladium‐catalysed Suzuki coupling, and silver‐mediated bromine displacement reactions were carried out successfully.