Transition-metal-mediated cascade reactions: the water-accelerated carboalumination-Claisen rearrangement-carbonyl addition reaction.
[Chemical reaction: See text] A three-step cascade reaction involving a water-accelerated catalytic carboalumination, a Claisen rearrangement, and a nucleophilic carbonyl addition converts terminal alkynes and allyl vinyl ethers into allylic alcohols containing up to three contiguous asymmetric carbon centers. Stoichiometric quantities of water as an additive increase the rate of the [3,3] sigmatropic rearrangement as well as the diastereoselectivity of the carbonyl addition process. Reaction products contain 1,6-diene functionalities that are readily cyclized to substituted cyclopentenes. An extension of this methodology to a sequence involving a [1,3] sigmatropic shift was feasible with a cyclopropylmethyl vinyl ether substrate.
Wipf
Peter
P
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. pwipf+@pitt.edu
Waller
David L
DL
Reeves
Jonathan T
JT
D000114:Acetylene / Q000737:chemistry; D002934:Cinnamates / Q000737:chemistry; D008670:Metals; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D028561:Transition Elements; D014753:Vinyl Compounds / Q000737:chemistry; D014961:X-Ray Diffraction
D002934:Cinnamates; D008670:Metals; D009942:Organometallic Compounds; D028561:Transition Elements; D014753:Vinyl Compounds; D000114:Acetylene