Synthesis of 5,6-dihydrobenz[c]acridines: a comparative study

Palladium-catalyzed three-component cyclization: Synthesis of hydroisoindol-1-ones from 2-bromocyclohex-1-enecarbaldehydes, anilines and carbon monoxide

“…When 1a was generally treated with 2a in DMF under carbon monoxide pressure in the presence of a catalytic amount of a palladium catalyst, hydroisoindol-1-one 3a was produced with concomitant formation of 1,2,3,4-tetrahydroacridine (4). It is known that b-halovinyl aldehydes are easily cyclized with primary arylamines to give quinolines via N-arylenaminoimine hydrochlorides [16]. The yield and distribution of the mixture of 3a and 4 was determined from the intensity of a clearly separated signal in 1 H NMR since it was difficult to separate these two products by simple elution on TLC without the loss of 4.…”

Halogen‐Exchange Fluorination of β‐Chlorovinyl Aldehydes – Unexpected Cascade Transformations in the Fluorination of 4‐Chloro‐2H‐chromene and 4‐Chloro‐2H‐thiochromene‐3‐carbaldehydes

“…Generally, β‐chloro or bromovinyl aldehydes are established valuable precursors to several medicinally important moieties, and various transformations of them viz. the metal catalyzed coupling with acetylenes, aryl boronic acids, and arylamines are reported. Similar transformations of β‐fluorovinyl aldehydes remain scanty in literature.…”

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.…”