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FeCl 3 ·6H 2 O and TfOH as Catalysts for Allylic Amination Reaction: A Comparative Study
Author(s) -
Trillo Paz,
Baeza Alejandro,
Nájera Carmen
Publication year - 2012
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.201101844
Subject(s) - allylic rearrangement , chemistry , amination , catalysis , nucleophile , regioselectivity , nucleophilic substitution , substitution reaction , organic chemistry , reaction mechanism , lewis acids and bases , medicinal chemistry
The use of FeCl 3 · 6H 2 O and TfOH as readily available and easy‐to‐handle catalysts for the direct allylic amination reaction using a wide variety of nitrogenated nucleophiles onto different free allylic alcohols is described. Comparative studies between these catalysts, as representative Lewis and Brønsted acids are conducted, concluding that both are suitable catalysts for this transformation. The reactions are performed in a flask open to air and using technical grade 1,4‐dioxane. In light of the results obtained from this study it can be asserted that TfOH turned out to be slightly superior than the Fe III salt since similar or better yields are obtained in most of the cases using lower catalyst loadings and milder reaction conditions. A similar trend is observed when carbonucleophiles were employed in the allylic substitution reaction. Studies for the elucidation of the reaction mechanism are in agreement with a carbocationic intermediate, being the regioselectivity governed by the stability of the final product.