Palladium‐catalyzed carbonylative cyclization of 3‐bromoallyl alcohols leading to furan‐2(5H)‐ones

Abstract

Bromoallyl alcohols are carbonylatively cyclized under carbon monoxide pressure in toluene in the presence of a catalytic amount of Pd(OAc) 2 and PPh 3 along with Na 2 CO 3 to give furan-2(5H)-ones in good yields.

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

“…Performing the reaction in the absence of base under the molar ratio of [2]/[1a] = 5 resulted in a similar yield of 3a (entry 5). Among solvents examined under the employed conditions, THF and dioxane were shown to be the solvent of choice (entries 3,[6][7][8]. With other bases such as Na 2 CO 3 and NaOAc combined with PdCl 2 /dppp in MeCN, the yield of 3a was generally lower than that when Et 3 N was employed (entries [8][9][10].…”

“…Among solvents examined under the employed conditions, THF and dioxane were shown to be the solvent of choice (entries 3,[6][7][8]. With other bases such as Na 2 CO 3 and NaOAc combined with PdCl 2 /dppp in MeCN, the yield of 3a was generally lower than that when Et 3 N was employed (entries [8][9][10]. From the activity of several palladium precursors examined under the employed conditions, PdCl 2 combined with dppf [1,1′-bis(diphenylphosphino)ferrocene] exhibited similar catalytic activity to PdCl 2 combined with dppp (entries 3,[11][12][13][14].…”

“…[1][2][3][4][5][6] During the course of our ongoing studies directed towards palladium-catalyzed carbonylative cyclizations, we recently reported on the synthesis of several carbonylgroup-containing heterocycles such as furanones, [7][8][9] alkyl 2,5-dihydro-5-oxofuran-2-carboxylates, [10] hydroisoindol-1-ones, [11] 1-aryl-1H-pyrrol-2(5H)-ones [12] and maleic anhydrides [13] from β-bromo-α,β-unsaturated aldehydes and their derivatives using such a carbonylative cyclization. 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.…”

Palladium‐catalyzed three‐component cyclization of 2‐bromocyclohex‐1‐enecarboxylic acids with carbon monoxide and arylhydrazines leading to 2‐anilinohydroisoindoline‐1,3‐diones

“…[4,5] As part of our continuing studies directed towards transition metal-catalyzed cyclization reactions of β-bromo-α,β-unsaturated aldehydes and their derivatives, we have identified several new methods for the synthesis of various carbonyl group-containing heterocycles via palladium-catalyzed carbonylative cyclization (carbonylation followed by cyclization) under carbon monoxide pressure. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] β-Bromo-α,β-unsaturated aldehydes and their derivatives are readily prepared from α-methylene group-containing ketones by bromination under Vilsmeier-Haack conditions [20,21] and subsequent transformation, and the products can serve as valuable building blocks for the construction of various cyclic compounds. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Among such carbonlative cyclization reactions, we recently have shown that β-bromo-α,β-unsaturated carboxylic acids can be carbonylatively cyclized with 2,2-dimethylhydrazine under carbon monoxide pressure in the presence of a palladium catalyst to give 1-(dimethylamino)-1H-pyrrole-2,5-diones.…”

Microwave‐assisted copper powder‐catalyzed coupling and cyclization of β‐bromo‐α,β‐unsaturated amides with amidine hydrochlorides leading to pyrimidinones

“…Thus, such scaffold‐containing compounds have been synthesized and tested for biological activity. During the course of our continuing studies directed towards transition metal‐catalyzed cyclization reactions of β‐bromo‐α,β‐unsaturated aldehydes and their derivatives, we have identified several new methods for the synthesis of carbocyclic and heterocyclic compounds . β‐Bromo‐α,β‐unsaturated aldehydes and their derivatives are readily prepared from α‐methylene group‐containing ketones by bromination under Vilsmeier–Haack conditions and subsequent transformation, and the products can serve as valuable building blocks for the construction of various cyclic compounds .…”