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Gold‐Catalyzed Cycloisomerizations of Functionalyzed Cyclopropyl Alkynes: the Cases of Carboxamides and Alcohols
Author(s) -
FernándezGarcía Jesús M.,
Garro Hugo A.,
FernándezGarcía Laura,
GarcíaGarcía Patricia,
FernándezRodríguez Manuel A.,
Merino Isabel,
Aguilar Enrique
Publication year - 2017
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.201700264
Subject(s) - cyclopropane , chemistry , cycloisomerization , regioselectivity , ring (chemistry) , nucleophile , catalysis , alkyl , cascade , adduct , cascade reaction , medicinal chemistry , stereochemistry , combinatorial chemistry , organic chemistry , chromatography
Abstract Push‐pull alkynylcyclopropane derivatives are claimed as suitable and active substrates for gold‐catalyzed transformations. Thus, 2(3 H )‐azepinones can be readily prepared from alkynylcyclopropanecarboxamides through a nucleophilic addition/cyclopropane ring‐opening cascade process and, in this manuscript, the scope and the limitations of such reaction sequence are reported. The cascade reaction is general and occurs with complete regio‐ and quimioselection to form the seven‐membered heterocycles with the exception of primary alkyl‐substituted alkynylcyclopropanecarboxamides that render 4‐methoxy‐6‐oxo‐4‐enenitriles in moderate yields. Additionally, less activated alkynylcyclopropylmethanols undergo regioselective cycloisomerization at low temperature leading to oxabicyclo[4.1.0]heptanes. Notably, the cyclopropane ring opening of these adducts takes place under thermal conditions to form dihydropyranones.