title: Copper-catalyzed hydroalkylation of terminal alkynes.
abstract: We have developed a copper-catalyzed hydroalkylation of terminal alkynes using alkyl triflates as coupling partners and (Me(2)HSi)(2)O as a hydride donor. The hydroalkylation proceeds with excellent anti-Markovnikov regioselectivity and provides exclusively (E)-alkenes. We have demonstrated that both alkyl- and aryl-substituted alkynes can be used as substrates, together with 1° alkyl and benzylic triflates. Finally, the transformation can be accomplished in the presence of a wide range of functional groups. Overall, the new hydroalkylation reaction allows highly efficient and diastereospecific synthesis of (E)-alkenes from readily available terminal alkynes and alkyl triflates. On the basis of a preliminary mechanistic study, we propose that the hydroalkylation reaction involves copper hydride formation, hydrocupration of an alkyne, and alkylation of an alkenyl copper intermediate.
authors.affiliation: The Department of Chemistry, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Mycah R
authors.initials: MR
authors.lastname: Uehling
authors.forename: Alison M
authors.initials: AM
authors.lastname: Suess
authors.forename: Gojko
authors.initials: G
authors.lastname: Lalic