Merrifield Resin−C<sub>6</sub>H<sub>4</sub>CH<sub>2</sub>N<sub>3</sub>P(MeNCH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N: An Efficient Reusable Catalyst for Room-Temperature 1,4-Addition Reactions and a More Convenient Synthesis of Its Precursor P(MeNCH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N
作者:Reddy、John G. Verkade
DOI:10.1021/jo062505z
日期:2007.4.1
donors were efficiently catalyzed at room temperature by the title reusable Merrifield resin-supported catalyst. Advantages of this catalyst include a simple workup (filtration of the reaction mixture) and good to excellent product yields. We also report a substantially simplified synthesis of the commercially available strong nonionic base 1, a precursor to the title polymer-bound catalyst.
N-heterocyclic carbene catalyzed Michael additions have been revisited with 1,3-dialkyl- or 1,3-diarylimidazol(in)ium-2-carboxylates, that is, NHC center dot CO2 adducts, as the source of the free NHC catalysts in solution. Using these precatalysts, a number of efficient carba-, sulfa-, and phospha-Michael additions were achieved very conveniently, without the need for an external strong base to generate the NHC by deprotonation of an azolium salt. To further expand the scope of the procedure, some NHC-catalyzed sulfa-Michael/aldol organocascades were also investigated.
Synthesis of bicyclic cyclopentanols by photoreductive cyclization of .delta.,.epsilon.-unsaturated ketones
作者:D. Belotti、J. Cossy、J. P. Pete、C. Portella
DOI:10.1021/jo00372a018
日期:1986.10
Conversion of ketones having δ, ϵ-π-functions to cyclopentanols by zinc-trimethylchlorosilane
作者:E.J. Corey、Stephen G. Pyne
DOI:10.1016/s0040-4039(00)88033-8
日期:1983.1
XIE, ZHUO-FENG;SUEMUNE, HIROSHI;SAKAI, KIYOSHI, SYNTH. COMMUN., 19,(1989) N-6, C. 987-992