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Nickel( 0 )‐Mediated [3+2+2] and [2+2+2+1] Cyclization Reactions of Chromium Fischer Carbene Complexes and Alkynes
Author(s) -
Barluenga José,
Barrio Pablo,
López Luis A.,
Tomás Miguel,
GarcíaGranda Santiago,
AlvarezRúa Carmen
Publication year - 2003
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.200351216
Subject(s) - carbene , chromium , chemistry , reactivity (psychology) , alkyne , nickel , medicinal chemistry , organic chemistry , catalysis , medicine , alternative medicine , pathology
Dramatic changes in Fischer carbene reactivity occur in the presence of [Ni(cod) 2 ]. Thus, instead of Dötz [3+2+1] benzannulation giving substituted phenols, alkenyl carbene complexes incorporate two equivalents of alkyne in a [3+2+2] cyclization, while simple chromium carbene complexes undergo a [2+2+2+1] cyclization (see scheme). These cyclizations are regio‐ and diastereoselective. cod=1,5‐cyclooctadiene.