Catalytic Asymmetric Inverse-Electron-Demand Diels−Alder Reaction of N-Sulfonyl-1-Aza-1,3-Dienes

5.10 Hetero-Diels–Alder Reactions

“…90 Table 26 Inverse electron-demand aza-Diels-Alder reaction of aldimine 166 catalyzed by the Yb(III) complex (Scheme 39) Table 29). 91 In this reaction, a,bunsaturated imines 174 act as 1-aza-1,3-butadienes, and the N-(8-quinolyl) group is crucial for obtaining high yield and high enantioselectivity. The enantioselectivity strongly depends on the R 2 group of 174, whereas para-substituted aryl groups are compatible, sterically demanding 2-naphthyl group and sterically less-hindered vinyl group significantly reduce the enantioselectivities.…”

Reactivity of 1,2,3-triazole-substituted 1-azabutadienes (vinamidines)

“…The reaction of 1a,b with dimethyl 1,2,4,5-tetrazinedicarboxylate (35) (a Diels-Alder reaction with inverse electron demand 23 ) was also tried. When 1a was reacted with 1 equivalent of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (35) in dichloroethane at room temperature, vigorous gas evolution was observed, the solution turned yellow within few minutes and crystals were separated.…”

In vitro evaluation and in silico screening of synthetic acetylcholinesterase inhibitors bearing functionalized piperidine pharmacophores

“…11 Moreover, some of them have been found to possess enzyme inhibitory activity against farnesyl transferase (FTase is believed to play an important role in development of progeria and various forms of cancers) 10 or dihydroorotate dehydrogenase (DHODH) 5 and also found to be useful in Parkinson's disease involving the MAO-based mechanism. 12,13 Hence, the synthesis of highly functionalized piperidines has evoked much attention 14,15 as a result of which a number of methodologies have been developed involving a variety of catalytic systems in the recent past. 10,[15][16][17][18][19][20] Very recently, we have also developed a straightforward and efficient diastereoselective multicomponent one-pot protocol for the synthesis of diverse functionalized piperidine (FP) scaffolds in good yields using commercially available bismuth nitrate pentahydrate as an inexpensive and environmentally benign catalyst, from the reaction of aromatic aldehydes, acetoacetic esters, and amines in ethanol at room temperature.…”