Well-defined (N-heterocyclic carbene)–Ag(i) complexes as catalysts for A3 reactions

Abstract

The use of well-defined (N-heterocyclic carbene)-Ag(I) complexes for the A(3) reaction allows for the coupling of unactivated aldehydes at room temperature and very short reaction times.

An Efficient A3 Coupling Catalyst Based on a Silver Complex Bearing N‐Heterocyclic Carbene and Homoscorpionate Bis(3‐methyl‐mercaptoimidazolyl)borate Ligands

“…For example, some of these reactions require high reaction temperatures or a high percentage of catalyst loading is required to achieve higher yields of products . Among carbene ligands, N‐heterocyclic carbenes, commonly known as NHCs, are excellent sigma donor ligands and their electronic and steric properties are adjustable by changing the nature of substituents on the nitrogen atoms . While different salts or nanostructures of coinage metals have been utilized as catalysts for A 3 coupling reactions, reports in regards to the N‐heterocyclic complexes of these metals are rare.…”

Silver and gold-catalyzed multicomponent reactions

“…The suitability of NHC–Ag(I) complexes as catalysts for A 3 -coupling MCR was confirmed, and independently developed some years later by the research groups of Zou [14], Navarro [15] and Tang [16] (Fig. 1).…”

“…Bearing in mind the importance of the counter ion of the Ag complex, Navarro and co-workers developed a new saturated 1,3-bis(2,6-diisopropylphenyl)imidazolium (SIPr) silver complex, characterized by the presence of a less bulky acetoxy anion [15]. The new NHC–Ag(I) complex displayed a broad scope in A 3 -coupling reactions, tolerating alkyl and arylaldehydes (also unactivated ones), cyclic and linear secondary aliphatic amines, and terminal alkyl/aryl alkynes.…”

Angled Vortex Fluidic Mediated Multicomponent Photocatalytic and Transition Metal‐Catalyzed Reactions

“…The tube was then capped tightly and rotated in the VFD at 3000, 5000, or 7000 rpm with at ilt angle of 15, 45, or [62] 7-(CH 2 ) 5 -4-MeOPhP h8 1(61) [63] 8-(CH 2 ) 4 -4-MeOPhP h8 4(87) [60] 9-(CH 2 ) 2 O(CH 2 ) 2 -C 6 H 11 Ph 90 (90) [ Optimization of reaction conditions for the coupling of morpholine,benzaldehyde, and phenylacetylene with AuBr 3 A1 0mmN MR tube was charged with morpholine (100 mL, 1.1 mmol), benzaldehyde (100 mL, 1.0 mmol), and phenylacetylene (160 mL, 1.5 mmol), with AuBr 3 (4 mg, 1mol %) in water (1 mL). The tube was then capped tightly and rotated in the VFD at 3000, 5000, or 7000 rpm with at ilt angle of 15, 45, or [62] 7-(CH 2 ) 5 -4-MeOPhP h8 1(61) [63] 8-(CH 2 ) 4 -4-MeOPhP h8 4(87) [60] 9-(CH 2 ) 2 O(CH 2 ) 2 -C 6 H 11 Ph 90 (90) [ Optimization of reaction conditions for the coupling of morpholine,benzaldehyde, and phenylacetylene with AuBr 3 A1 0mmN MR tube was charged with morpholine (100 mL, 1.1 mmol), benzaldehyde (100 mL, 1.0 mmol), and phenylacetylene (160 mL, 1.5 mmol), with AuBr 3 (4 mg, 1mol %) in water (1 mL).…”

“…Optimization of VFD reaction conditions for the coupling of N-phenyltetrahydroisoquinoline,acetic acid, and cyclohexyl isocyanide with Rose Bengal A1 0mmN MR tube was charged with N-phenyltetrahydroisoquinoline (52 mg, 0.25 mmol), acetic acid (17 mL, 0.3 mmol), cyclohexyl isocyanide (37 mL, 0.3 mmol), Rose Bengal (2 mg, 1mol %), and acetonitrile (2 mL). The tube was then capped tightly and rotated in the VFD at 3000, 5000, or 7000 rpm with at ilt angle of 15, 45, or [62] 7-(CH 2 ) 5 -4-MeOPhP h8 1(61) [63] 8-(CH 2 ) 4 -4-MeOPhP h8 4(87) [60] 9-(CH 2 ) 2 O(CH 2 ) 2 -C 6 H 11 Ph 90 (90) [60]…”