title: Rh(I)-catalyzed CO gas-free carbonylative cyclization reactions of alkynes with 2-bromophenylboronic acids using formaldehyde.
abstract: The rhodium(I)-catalyzed reaction of alkynes with 2-bromophenylboronic acids in the presence of paraformaldehyde resulted in a CO gas-free carbonylative cyclization, yielding indenone derivatives. [RhCl(BINAP)](2) and [RhCl(cod)](2) were responsible for the decarbonylation of formaldehyde and the subsequent carbonylation of alkynes with 2-haloboronic acids, respectively, leading to efficient whole carbonylation. Sterically bulky and electron-withdrawing groups on unsymmetrically substituted alkynes favored the alpha-position of indenones.
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST), Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Tsumoru
authors.initials: T
authors.lastname: Morimoto
authors.forename: Kae
authors.initials: K
authors.lastname: Yamasaki
authors.forename: Akihisa
authors.initials: A
authors.lastname: Hirano
authors.forename: Ken
authors.initials: K
authors.lastname: Tsutsumi
authors.forename: Natsuko
authors.initials: N
authors.lastname: Kagawa
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Kakiuchi
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Harada
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Fukumoto
authors.forename: Naoto
authors.initials: N
authors.lastname: Chatani
authors.forename: Takanori
authors.initials: T
authors.lastname: Nishioka