Sequential Michael Addition-Carbocyclization Reactions: A Palladium-Mediated Approach to Highly Functionalized 3-Methylenetetrahydrofurans
作者:Xavier Marat、Nuno Monteiro、Geneviève Balme
DOI:10.1055/s-1997-5755
日期:1997.7
A one-pot procedure for the preparation of highly functionalized 3-methylenetetrahydrofurans is described. The methodology is based on an oxygen nucleophile initiated Michael addition of propargyl alcohols to alkylidene or arylidenemalonates followed in situ by a palladium-mediated exo-dig cyclization.
Copper-Exchanged Tungstophosphoric Acid: An Efficient and Reusable Heteropoly Acid for the Synthesis of 2,3,4,5-Tetrahydro-4-methylidenefuran Derivatives
作者:Seema Aravind、Narayana Reddy
DOI:10.1002/hlca.201400269
日期:2015.4
Copper‐exchanged tungstophosphoricacid (Cu‐TPA) is found to catalyze efficiently the coupling of propargyl alcohol (prop‐2‐yn‐1‐ol) with (arylmethylidene)malononitriles to afford the corresponding 2,3,4,5‐tetrahydro‐4‐methylidenefuran derivatives in good yields and with high selectivity. The catalyst is recycled and reused for three‐to‐four subsequent runs with a minimal decrease of activity.