2026-05-27T02:33:58Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/38952022-12-19T09:36:20Zcom_10259_3593com_10259_5086com_10259_2604col_10259_3594

00925njm 22002777a 4500 dc Sanjuán Cortázar, Ana María author Rashid, Muhammad A. author García García, Patricia author Martínez Cuezva, Alberto author Fernández Rodríguez, Manuel A. author Rodríguez, Félix author Sanz Díez, Roberto author 2015-02 Indenes and related polycyclic structures have been efficiently synthesized by gold(I)-catalyzed cycloisomerizations of appropriate ortho-(alkynyl)styrenes. Disubstitution at the terminal position of the olefin was demonstrated to be essential to obtain products originating from a formal 5-endo-dig cyclization. Interestingly, a complete switch in the selectivity of the cyclization of o-(alkynyl)-α-methylstyrenes from 6-endo to 5-endo was observed by adding an alcohol to the reaction media. This allowed the synthesis of interesting indenes bearing an all-carbon quaternary center at C1. Moreover, dihydrobenzo[a]fluorenes can be obtained from substrates bearing a secondary alkyl group at the β-position of the styrene moiety by a tandem cycloisomerization/1,2-hydride migration process. In addition, diverse polycyclic compounds were obtained by an intramolecular gold-catalyzed alkoxycyclization of o-(alkynyl)styrenes bearing a nucleophile in their structure. Finally, the use of a chiral gold complex allowed access to elusive chiral 1H-indenes in good enantioselectivities 0947-6539 http://hdl.handle.net/10259/3895 10.1002/chem.201405789 asymmetric catalysis cyclization cycloisomerization gold indenes Gold(I)-Catalyzed Cycloisomerizations and Alkoxycyclizations of ortho-(Alkynyl)styrenes