Intramolecular [4 + 2] cycloadditions of 1,3-enynes or arylalkynes with alkenes with highly reactive cationic phosphine Au(I) complexes.
New Au(I) complexes with bulky, biphenyl phosphines are the most reactive catalysts for the cyclizations of enynes. 1,6-Enynes with an aryl ring at the alkyne give 2,3,9,9a-tetrahydro-1H-cyclopenta[b]naphthalenes by a 5-exo-dig cyclization followed by a Nazarov-type ring expansion. 1,8-Dien-3-ynes also cyclize by a 5-exo-dig pathway to form hydrindanes.
Nieto-Oberhuber
Cristina
C
Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Spain.
López
Salomé
S
Echavarren
Antonio M
AM