1213-78-1Relevant articles and documents
Synthesis of 1H-inden-1-ol derivatives via rhodium-catalyzed annulation of o-acylphenylboronic acids with alkynes
Matsuda, Takanori,Makino, Masaomi,Murakami, Masahiro
, p. 1416 - 1417 (2005)
A rhodium-catalyzed annulation reaction of o-formyl-phenylboronic acid with alkynes occurred regioselectively at room temperature to give substituted 1H-inden-1-ol derivatives. o-Acetylphenylboronic acid also underwent the annulation reaction at 80°C to a
Cobalt-catalyzed regioselective carbocyclization reaction of o-iodophenyl ketones and aldehydes with alkynes, acrylates, and acrylonitrile: A facile route to indenols and indenes
Chang, Kuo-Jui,Rayabarapu, Dinesh Kumar,Cheng, Chien-Hong
, p. 4781 - 4787 (2004)
An efficient cobalt-catalyzed carbocylization for the synthesis of indenols and indenes and a new method for reductive decyanation are described. 2-Iodophenyl ketones and aldehydes 1a-g undergo carbocyclization with various disubstituted alkynes 2a-k in the presence of Co(dppe)I2 and zinc powder in acetonitrile at 80 °C for 3 h to afford the corresponding indenol derivatives 3a-s and 4a-m in good to excellent yields. For some unsymmetrical alkynes, the carbocyclization was remarkably regioselective, affording a single regioisomer. The cobalt-catalyzed carbocyclization reaction was successfully extended to the synthesis of indene derivatives. Thus, the reaction of 2-iodophenyl ketones and aldehydes (1) with acrylates H2C=CHCO 2R (7a-d) and acrylonitrile H2C= CHCN (7e) proceeds smoothly in the presence of Co(dppe)Cl2/dppe and zinc powder in acetonitrile at 80 °C for 24 h to afford the corresponding indenes 8a-k and 9a-c in moderate to good yields. Interestingly, when 7e was employed for the carbocylization, reductive decyanation also occurred to give an indene derivative without the cyano functionality. A possible mechanism for this cobalt-catalyzed carbocyclization reaction is also proposed.