Pd/C-Catalyzed coupling and cyclization of β-bromo-α,β-unsaturated carboxylic acids with terminal alkynes leading to alkylidenefuranones

A recyclable metal-organic framework MOF-199 catalyst in coupling and cyclization of β-bromo-α,β-unsaturated carboxylic acids with terminal alkynes leading to alkylidenefuranones

“…The acid 1a also coupled and cyclized with terminal alkynes (2e and 2f) having straight and branched alkyl chains to give the corresponding alkylidenefuranones (3d and 3e) in good yields. These results clearly indicate that the present catalytic system exhibit higher catalytic activity compared with Pd on C/CuI/PPh 3 and CuI/L-proline [5]. The yields under both catalytic systems are shown in parentheses of Table 2.…”

“…Removal of the solvent from the filtrate left an oil, which was purified by thin layer chromatography (silica gel, ethyl acetate/hexane) to give desired products 3. Except for 3m, all products were characterized by spectroscopic comparison with authentic samples synthesized by our recent reports [5]. …”

“…b-bromo-a,b-unsaturated aldehydes and their derivatives are readily prepared from a-methylene group-containing ketones by bromination under Vilsmeier-Haack conditions [3], and the products can serve as valuable building blocks for the construction of various cyclic compounds [4]. Among such cyclization reactions, we have shown that b-bromo-a,b-unsaturated carboxylic acids are coupled and cyclized with terminal alkynes in the presence of Pd on C/PPh 3 or CuI/amino acid to give alkylidenefuranones [5]. However, these protocols have some drawbacks requiring an expensive consumable transition metal catalyst or an additional ligand.…”

CuI/amino acid catalysis in coupling and cyclization of β‐bromo‐α,β‐unsaturated carboxylic acids with terminal alkynes leading to alkylidenefuranones

“…Table shows several results for the attempted coupling and cyclization of 2‐bromocyclohex‐1‐enecarboxylic acid ( 1a ) with phenylacetylene ( 2a ), leading to (3 Z )‐3‐benzylidene‐4,5,6,7‐tetrahydroisobenzofuran‐1(3 H )‐one ( 3a ) under reaction variants such as several kinds of amino acid, solvent and base. Treatment of 1a with 1.5 equiv.…”

Palladium‐catalyzed carbonylative cyclization of β‐bromo‐α,β‐unsaturated carboxylic acids with 2,2‐dimethylhydrazine leading to 1‐(dimethylamino)‐1H‐pyrrole‐2,5‐diones

“…The β-bromo-α,β-unsaturated aldehydes and their derivatives can be readily prepared from the corresponding α-methylene-containing ketones by the bromination conditions of the Vilsmeier-Haak reaction [14,15] and subsequent transformation and used as a building block for the construction of various cyclic compounds. [16][17][18][19][20][21][22][23][24][25][26][27] Under these circumstances, among the synthesis of carbonyl-group-containing heterocycles via such a carbonylative cyclization, β-bromo-α, β-unsaturated carboxylic acids were found to be cyclized with primary amines in the presence of a palladium catalyst under carbon monoxide pressure to afford N-alkylmaleimides.…”