Thiol-mediated tandem Michael–aldol reaction: a convenient method for the synthesis of fused cyclopentenones

Ligand‐free CuI‐catalyzed coupling and cyclization of β‐bromo‐α,β‐unsaturated amides with formamide leading to pyrimidinones

“…As part of our continuing studies directed towards transition metal‐catalyzed cyclization reactions, we recently disclosed new synthetic methods for the formation of several carbo‐ and heterocyclic compounds using β‐bromo‐α,β‐unsaturated aldehydes and their derivatives via such an intrinsic coupling and 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 and subsequent transformation and used as a building block for the synthesis of versatile cyclic compounds . In connection with this report, Ma et al .…”

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

“…[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. [39] The present work arose during the course of the application of this protocol to the reaction with arylhydrazines.…”

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

“…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 . Among such heterocyclic compounds, we also have shown two examples for the synthesis of pyrimidinone scaffold.…”