Pd(0)-Catalyzed Intramolecular “Ylide-Ullmann-Type” Cyclization of Carbonyl-Stabilized Phosphonium Ylides and Access to Phosphachromones by Exocyclic P–C Cleavage
An unprecedented palladium-catalyzed intramolecular Ullmann-type cyclization of carbonyl-stabilized phosphonium ylides with aryl bromides was successfully developed. Furthermore, a base-promoted chemoselective hydrolysis of exocyclic P-C bond of the corresponding phosphonium salts delivered various phosphachromones. Excellent selectivity and high efficiency and good functional group tolerance were
Variations on the Blaise Reaction: Synthesis of 3,5-Dioxopentanoates and 3-Amino-5-oxopent-3-enoates
作者:H. Rao、Nandurka Muthanna
DOI:10.1055/s-0035-1561662
日期:——
(α-cyano ketones) with ethyl bromoacetate. The reaction is a variation on the classical Blaise reaction, tuned to the synthesis of trifunctional compounds having 3,5-diketo ester or 3-enamino 5-keto ester functional groups. Our studies revealed that the Blaise reaction on the nitrile occurs in preference to the Reformatsky reaction on the neighboring ketone when the two functional groups are in a geminal