phosphoric acid cooperatively catalyzedasymmetricthree-componentreaction of enynal with alcohol and imine, affording chiral α-furyl-β-amino carboxylates in good to high yields with generally excellent stereoselectivity. The successful introduction of enynal as a carbene precursor in this reaction provides an expeditious track to prepare complex furan derivatives with adjacent quaternary and tertiary stereocenters
[reaction: see text] In the presence of rhodium catalyst, (2-furyl)carbenoids generated from conjugated ene-yne-carbonyl compounds 1 efficiently undergo carbene transfer reactions with allylic sulfides followed by [2,3]sigmatropic rearrangement of sulfur ylides to give furan-containing sulfides in good yields. When diallyl sulfide is employed, heteroatom-containing polycyclic compounds are obtained
Catalytic Nucleophilic Addition Reaction to (2-Furyl)carbene Intermediates Generated from Carbonyl–Ene–Ynes
作者:Koji Miki、Yumiko Kato、Sakae Uemura、Kouichi Ohe
DOI:10.1246/bcsj.81.1158
日期:2008.9.15
Rhodium- and chromium-catalyzed addition reactions of various σ-bonds, such as C–H, N–H, O–H, Si–H, and S–H bonds, to (2-furyl)carbenoids in situ generated from conjugated carbonyl–ene–yne compound...