title: Hydration of terminal alkynes catalyzed by water-soluble cobalt porphyrin complexes.
abstract: Water-soluble cobalt(III) porphyrin complexes were found to promote the hydration of terminal alkynes to give methyl ketones. The alkyne hydration proceeded in good to excellent yield with 0.1 to 2 mol % cobalt catalyst 1 and was compatible with the presence of acid/base- or redox-sensitive functional groups such as alkyl silyl ethers; allyl ethers; trityl ethers; benzyl ethers; carboxylic esters; boronic esters; carboxamides; nitriles; and nitro, iodo, and acetal groups. Some of the alkyne substrates tested here are otherwise difficult to hydrate. The alkyne hydration can be performed on a gram scale, and the catalyst can be recovered by aqueous workup.
authors.affiliation: Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Tachinami
authors.forename: Takuho
authors.initials: T
authors.lastname: Nishimura
authors.forename: Richiro
authors.initials: R
authors.lastname: Ushimaru
authors.forename: Ryoji
authors.initials: R
authors.lastname: Noyori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Naka
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D012995:Solubility; D014867:Water / Q000737:chemistry*
chemical_list: D000480:Alkynes; D007659:Ketones; D008665:Metalloporphyrins; D014867:Water; D003035:Cobalt