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A novel series of 1,2,3-triazoles is synthesized by 1,3-dipolar cycloaddition of aromatic azides and terminal alkynes containing 1,2,4-triazole/1,3,4-oxadiazole in presence of Cu(I) catalyst in aqueous medium. The compounds are characterized by spectral and analytical data. The novel triazoles demonstrate moderate to excellent antibacterial activity and good docking score. [ABSTRACT FROM AUTHOR]

The combined use of simple copper salts and quaternary ammonium salts in a low‐boiling‐point solvent is presented as a new strategy for terminal alkyne carboxylation with CO2 under ambient conditions. The ligand‐free copper‐catalyzed carboxylation was achieved with CuCl, nBu4NOAc, and K2CO3 in MeCN to produce various propiolic acids in high to excellent yields. [ABSTRACT FROM AUTHOR]

The utilization of carbon dioxide (CO 2) from dilute gas as C1 feedstock for synthesis of high-value chemicals such as α-alkylidene cyclic carbonates is one of the promising approaches towards mitigating the increasing atmospheric CO 2 concentration. Consequently, herein, we demonstrate the application of UiO-MOF functionalized with bipyridine sites for facile anchoring of catalytically active noble metal-free copper (I) sites by post-synthetic treatment. The Cu(I) anchored UiO-MOF exhibits an excellent catalytic activity for coupling CO 2 with propargylic alcohols affording α-alkylidene cyclic carbonates, valuable commodity chemicals at mild conditions of 1 atm of CO 2 (balloon). Furthermore, the MOF catalyst showed good activity for fixation carbon dioxide from dilute gas (CO 2 :N 2 = 13:87%) condition. The superior catalytic performance of Cu(I)@UiO-MOF over the homogeneous counterpart has been attributed to a synergistic effect of high CO 2 -philicity of MOF and catalytic activity of copper (I) sites exposed in the 1D channels of the MOF. The catalyst can be recycled up to five cycles with retention of catalytic efficiency and its heterogeneity enjoyed over the reaction period. This work demonstrates the rational integration of non-noble metal catalytic sites in functionalized frameworks for the efficient fixation of CO 2 from dilute gas into fine chemicals. Rational construction of noble metal-free Cu(I) anchored Zr-MOF for selective capture and fixation of CO 2 with propargylic alcohols at atmospheric pressure conditions has been demonstrated. [Display omitted] • Noble metal-free Cu(I)@MOF catalyst for the effective fixation of CO 2 at ambient conditions is demonstrated. • The Cu(I)-anchored MOF exhibits selective CO 2 adsorption with high interaction energy of 44.13 kJ/mol. • The Cu(I)@MOF catalyst showed efficient catalytic activity for fixation of CO 2 from dilute gas at atmospheric pressure conditions. • The catalyst shows high thermal stability and recyclability. [ABSTRACT FROM AUTHOR]

A protocol has been developed to prepare 1,2-allenyl ketones using molecular oxygen in air or pure oxygen as the oxidant from 2,3-allenylic alcohols with moderate to good yields under mild conditions. In this reaction CuCl (20 mol %) with 1,10-phenanthroline (10 mol %) and bipyridine (10 mol %) was used as the catalyst. It is interesting to observe that the use of the mixed ligands is important for the higher yields of this transformation: With the monoligand approach developed by Markó et al., the yields are relatively lower.

Phosphine ligands have been successfully used along with Cu(I) for several catalytic reactions, nevertheless these ligands were less explored relatively for carbene involved reactions owing to the formation of carbene-phosphine ylides. In this report we successfully used three different phosphine stabilized Cu(I) complexes ( 1 – 3 ) as catalysts for chemoselective carbene insertion into the N–H bond of different aromatic amines over the formation of olefin (carbene dimerized product). In order to understand the substrate scope, different α-diazo esters have been reacted with large number of amines and all the reactions produced reasonably good yields under normal experimental conditions (38 examples). All the carbene inserted products have been isolated by column chromatography and fully characterized using standard spectroscopic techniques without any ambiguities. Several control reactions have been conducted in order to understand the importance of the type of phosphine ligands used in the catalysts 1 – 3 and found that without these catalysts we observed less selectivity (more of olefin as the product over N–H inserted product) and low yield. From this present study, it can be noted that the rigid framework phosphine ligands would be the better choice for carbene chemistry. The results obtained from the current studies would inspire chemists to develop more novel Cu(I)-phosphine catalysts for carbene related reactions including asymmetric versions in the near future. [ABSTRACT FROM AUTHOR]

An efficient protocol for the synthesis of a variety of azobenzenes and hydrazines from aromatic amines under mild reaction conditions is developed using Cu(I) catalyst. The copper cataylst used in this study comprises of CuBr, DMAP and AIBN. The plausible proposed mechanism for this dehydrogenative homo coupling of aromatic amines is depicted. [ABSTRACT FROM AUTHOR]

DABCO (1,4-diazabicyclo[2.2.2]octane) based Cu(I) metal organic framework (here after represented as Cu(I)-MOF) catalyzed Sonogashira cross-coupling reaction of iodobenzene and phenylacetylene was conducted smoothly to afford diphenylacetylene in excellent yield under N 2 atmosphere. For comparative study, piperidine based Cu(I) clusters were also investigated. Among these catalysts, Cu(I)-MOF exhibited higher activity with good selectivity for the C–C cross-coupled product. Cu(I) catalysts investigated in this study exhibited similar activity in the C–C homo-coupling reaction of phenylacetylene in O 2 atmosphere. Application of these catalysts was extended in the C–N coupling reactions between phenylboronic acid and aromatic/aliphatic/heterocyclic amines. Cu(I)-MOF can be readily recovered from the reaction mixture and reused for several cycles without loss in the catalytic activity. [ABSTRACT FROM AUTHOR]

Abstract: The catalytic asymmetric decarboxylative aldol-type reaction between aldehydes and cyanocarboxylic acids and Mannich-type reaction between aldimines and cyanocarboxylic acids were developed. α,α,β-Trisubstituted-β-hydroxy nitriles bearing contiguous all-carbon quaternary and trisubstituted stereocenters were produced with moderate enantio- and diastereoselectivity in the presence of 10 mol % CuOAc–TANIAPHOS (or DTBM-SEGPHOS) complex in the aldol-type reaction. α,α,β-Trisubstituted-β-amino nitriles containing contiguous all-carbon quaternary and trisubstituted stereocenters were produced with moderate to high enantio- and diastereoselectivity using 5 mol % CuOAc–(R)-DTBM-SEGPHOS complex in the Mannich-type reaction. These reactions proceed through Cu(I)-catalyzed decarboxylative nucleophile generation, followed by the addition of the resulting chiral Cu-ketenimide to aldehydes or imines. Because the reactions proceed under very mild conditions at nearly neutral pH, the reactions are applicable to a wide range of substrate combinations, including both aromatic and aliphatic substrates. Finally, α,α,β-trisubstituted-β-amino nitriles were converted to β2,2,3-amino acid derivatives through simple acidic hydrolysis without any racemization and epimerization. [Copyright &y& Elsevier]

Abstract: A multicomponent one-pot reaction involving propargyl glycosides, methoxy-substituted aromatic aldehydes and aromatic amines using Cu(I) as catalyst is described, which provides an efficient and practical route to synthesize several quinoline-based glycoconjugates in good yield. [Copyright &y& Elsevier]

Abstract: Tertiary amines with three different substituents were obtained in a single step by the CuCl/B(OMe)3 or B(OMe)3-catalyzed reaction of α-chlorine substituted allylsilanes, alkyl halides, and primary amines. [Copyright &y& Elsevier]

The synthesis of 1,2,3-triazolyl-5-diethylphosphonate was studied by the domino reaction of benzyl azide, phenylacetylene and diethyl phosphite. The effect of the reaction stoichiometry, the atmosphere and the amount of the catalyst were investigated. [ABSTRACT FROM AUTHOR]

An efficient CuI catalyzed intramolecular Ullmann-type C−N coupling reaction is described here. Newly substituted 1H-benzo[4,5]imidazo[1,2- a ]pyrrolo[3,4- c ]pyridine-1,3,5(2H, 11H)-trione has been easily synthesized from ortho halogenated N-substituted pyrrolo[3,4- c ]pyridine-1,3,6(5H)-triones in presence of CuI catalyst and K 2 CO 3 base without any ligand. This procedure is based on intramolecular Ullmann-type reaction and provides a proficient method of making fused tetracyclic heterocycles. Image 1 • First report of synthesis of Substituted 1H-benzo[4,5]imidazo[1,2-a]pyrrolo[3,4-c]pyridine-1,3,5(2H, 11H)-trione. • Cu (I) catalysed intramolecular Ullmann-type C−N coupling reaction has been followed. • Fused tetracyclic heterocycles synthesized using CuI as catalyst and K 2 CO 3 base without any ligand. • Synthesised compounds are biologically important containing both benzimidazole and pyrrolo[3,4- c ]pyridine rings. [ABSTRACT FROM AUTHOR]

A protocol has been developed to prepare 1,2-allenyl ketones using molecular oxygen in air or pure oxygen as the oxidant from 2,3-allenylic alcohols with moderate to good yields under mild conditions. In this reaction CuCl (20 mol %) with 1,10-phenanthroline (10 mol %) and bipyridine (10 mol %) was used as the catalyst. It is interesting to observe that the use of the mixed ligands is important for the higher yields of this transformation: With the monoligand approach developed by Markó et al., the yields are relatively lower.