Cu(OTf)2: a reusable catalyst for high-yield synthesis of 3,4-dihydropyrimidin-2(1H)-ones

The Three‐Component Biginelli Reaction: A Combined Experimental and Theoretical Mechanistic Investigation

“…Monitoring the reaction of benzaldehyde (2 a) and ethyl acetoacetate (3 a) in CD 3 OH/HCl by 1 H and 13 C NMR spectroscopy, he found no evidence for an aldol reaction or any other reaction between the two components at room temperature. Further, Kappe also observed the formation of bisureide 5 a (Scheme 3) by 1 H NMR spectroscopy (CD 3 OH, HCl), but no other intermediate (11 a or 12 a) was detected (Scheme 3).…”

“…[2][3][4][5][6][7][8][9][10][11][12] Bignelli reactions can be performed under a variety of conditions, and several improvements of the experimental procedures have been reported in recent years. Although it has been traditionally catalyzed by strong Brønsted acids, Lewis acids such as LiClO 4 , LaCl 3 , InCl 3 , BiA C H T U N G T R E N N U N G (OTf) 3 , BiCl 3 , MnA C H T U N G T R E N N U N G (OAc) 3 , CuA C H T U N G T R E N N U N G (OTf) 2 , FeCl 3 , ZrCl 4 , or SnCl 2 [13][14][15][16][17] are now being increasingly used. The use of ionic liquids, [18][19][20] microwave irradiation, [7,[21][22][23][24][25][26][27][28][29][30][31] solid-phase reagents, [12,32,33] and polymer-supported catalysts have also been reported.…”

Copper(II) Triflate: A Versatile Catalyst for the One‐Pot Preparation of Orthogonally Protected Glycosides

“…For instance, CuA C H T U N G T R E N N U N G (OTf) 2 has been used to catalyze acetylation reactions, [13] and more recently was used as a mild glycosylation promoter. [14] In general, CuA C H T U N G T R E N N U N G (OTf) 2 is used in catalytic amounts and is water-stable, hence it can be easily recycled and reused without loss of activity, [15] which makes it very attractive for the synthetic chemist.…”

Synthesis of pyrimidine carboxamide derivatives catalyzed by uranyl nitrate hexa Hydrate with their antibacterial and antioxidant studies

“…Biginelli reaction takes place by mixing different substituted aldehydes, urea or thiourea, and an active 1,3-dicarbonyl compound in combination with different catalytic systems such as AcOH [14], ZrCl 4 [15], Cu(OTf) 2 [16], SiO 2 /H 2 SO 4 [17], La(OTf) 3 [18], CdCl 2 [19], 1-n-butyl-3-methyl imidazolium tetrafluoroborate [20], SiO 2 /NaHSO 4 [21], Pb(NO 3 ) 2 [22], NaCl [23], KSF clay [24], FeCl 3 [25], BiCl 3 [26], ion-exchange resin [27], LiBr [28] [32], Mn(OAc) 3 [33], InBr 3 [ 34], microwave [35][36][37][38] or ultrasound irradiation [39] and solvent-free conditions [40], Co(NO 3 ) 2 .6H 2 O [41], ZnCl 2 /TBAB [42]. In the last two decades microwave mediated reactions have been of great interest in organic synthesis because of their shorter reaction times and high yields of products with good selectivity.…”