Palladium(II)-Catalyzed Synthesis of α-Alkylidene-γ-butyrolactams from N-Allylic 2-Alkynamides. Total Synthesis of (±)-Isocynodine and (±)-Isocynometrine

Abstract

An efficient method for preparing alpha-alkylidene-gamma-butyrolactams via the Pd(II)-catalyzed cyclization of acyclic N-allylic 2-alkynamides via halopalladation, intramolecular olefin insertion, and beta-heteroatom elimination was developed. The reaction is less influenced by the leaving group and the concentration of the halide ions in comparison with the cyclization of acyclic alkynoates. The total syntheses of (+/-)-isocynodine and (+/-)-isocynometrine were realized using this method.

Control of the β-Hydride Elimination Making Palladium-Catalyzed Coupling Reactions more Diversified

“…Synthesis of a-alkylidene-c-butyrolactams from N-allylic-2-alkynamides [59]. N-Allylic alkyamides were cyclized using the similar reaction conditions reported for the cyclization of allylic alkynoates [15,16] (scheme 11).…”

Addition of allyl bromide to phenylacetylene catalyzed by palladium on alumina and its application to a continuous flow synthesis

“…1) [1][2][3][4][5][6]. The resulting compounds can be easily coupled with organotin reagents [7], terminal alkynes [8], just to name a few [9][10][11][12][13][14][15], to lead to a variety of functionalized alkenes. In terms of easy separation of catalysts and products (for recent reviews for heterogenous catalysis, see [16][17][18][19]), we became interested in the ability of palladium on alumina [20][21][22][23][24][25] and carbon for the above transformation.…”

The Reaction of Electron-Deficient Cyclopropane Derivatives with Aromatic Amines

“…[1,2] It also serves as a key intermediate in the synthesis of biologically and pharmaceutically useful molecules. [2,3] Recently, in our study of the chemistry of electron-deficient cyclopropane derivatives, [4] we found that many weak nucleophiles (e.g., water, [5] methanol, [6] amine, [7][8][9] thiophenol, [10] and arsonium ylide [11] ) can react with electrondeficient cyclopropane derivatives to produce many types of new compounds with high stereoselectivity. In this article, we report that cis-1-benzoyl-2-aryl-6,6-dimethyl-5,7-dioxo-spiro-[2,5]-4,8-octadiones (1a-d) (X ¼ CH 3 , H, Cl, NO 2 ) react with aromatic amines (2a-…”