ChemInform Abstract: Direct Synthesis and Antimicrobial Evaluation of Structurally Complex Chalcones.

Simple and solvent free practical procedure for chalcones: An expeditious, mild and greener approach

The synthesis of a novel class of reversible addition‐fragmentation chain transfer (RAFT) agents—based on quantum‐chemical ab initio calculations—having methylsulfonyl and phenylsulfonyl moieties as Z‐group is described. The resulting C‐sulfonyldithioformate transfer agents [benzyl methylsulfonyldithioformate (MSDTF) and benzyl phenylsulfonyldithioformate (PSDTF)] feature extremely strong electron deficient CS double bonds and should thus be suitable to undergo rapid hetero Diels‐Alder (HDA) reactions with variable dienes under mild (i.e., ambient and catalyst free) reaction conditions. It can be demonstrated via a series of model reactions, whose outcome is monitored via electrospray ionization mass spectrometry (ESI–MS), that C‐sulfonyldithioformate based RAFT agents undergo HDA reactions with a series of diene‐capped macromolecules (10 min < reaction time < 24 h) at ambient temperatures (T ≈ 25 °C) with reaction times ranging from 24 h (for open chain dienes) to a few minutes (for cyclopentadiene) in the absence of any catalysts. Concomitantly, PSDTF is able to efficiently mediate the polymerization of isobornyl acrylate (iBA) with living characteristics (2300 < Mn (g/mol) < 16,000, 1.08 < PDI < 1.31). In a subsequent step, it is demonstrated that conjugates of poly(iBA) and polystyrene can be constructed under mild reaction conditions (reaction time < 10 min, T ≈ 25 °C, Mn ≈ 6000 (g/mol), PDI ≈ 1.3, no catalyst). In addition, we highlight that sulfonyldithioformate type RAFT agents are such effective dienophiles that they can undergo HDA reactions with certain monomers, including styrene. While such a strong HDA activity limits their use in polymerizations, it opens an avenue for catalyst free efficient surface modification reactions under mild conditions with variable dienes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6053–6071, 2009

Glycosyl isoquinoline‐1‐carboxylate was developed as a novel benchtop stable and readily available glycosyl donor. The glycosylation reaction was promoted by the inexpensive Cu(OTf)2 salt under mild reaction conditions. The copper isoquinoline‐1‐carboxylate salt was precipitated from the solution and thus rendered a traceless leaving group. Surprisingly, the proton from the acceptor was absorbed by the precipitated metal complex and the reaction mixture remained at neutral pH. The copper‐promoted glycosylation was also proven to be completely orthogonal to the gold‐promoted glycosylation, and an iterative synthesis of oligosaccharides from benchtop stable anomeric ester building blocks becomes possible under mild reaction conditions.

A one‐pot four‐component synthesis of bis‐tetrazolopiperazines in moderate to high yields is described. The reaction consists of condensation of aldehydes or cyclic ketones with piperazine, trimethylsilyl azide, and isocyanides. High reaction efficiency, short reaction time, mild reaction condition, use of simple experimental procedure, and prompt isolation of the products are some advantages of this protocol.

Eaton's reagent efficiently catalyzed the Claisen-Schmidt condensation reaction of aryl aldehydes with aromatic and cyclic ketones under solvent free microwave irradiation conditions to afford mono and bis-chalcone derivatives. The present approach offers several advantages such as shorter reaction times, cleaner reactions, good yields, inexpensive reagent and mild reaction conditions

A simple, efficient and ecofriendly one pot synthesis protocol has been developed for the synthesis of N-substituted decahydroacridine-1,8-diones by using an efficient and recyclable solid acidic silica supported MoO3/SiO2 catalyst from a condensation of aldehyde, amine and cyclic 1,3-diketone in THF. The reaction using MoO3/SiO2 catalyst was carried out under mild condition with very high yields up to 92%. The present approach of this methodology offers several advantages such as shorter reaction times, good yields, low cost, environmentally benign, milder reaction conditions, easy recovery of catalyst and reusability.

Ir-catalyzed photoredox cascade radical annulation reactions toward phosphinimides bearing quaternary carbon center at room temperature

A new versatile method for the C–P bond formation of (hetero)aryl halides with trimethyl phosphite via a UV-induced photo-Arbuzov reaction, accessing diverse phosphonate-grafted arenes, heteroarenes and co-facially stacked cyclophanes under mild reaction conditions without the need for catalyst, additives, or base is developed. The UV-induced photo-Arbuzov protocol has a wide synthetic scope with large functional group compatibility exemplified by over 30 derivatives. Besides mono-phosphonates, di- and tri-phosphonates are accessible in good to excellent yields. Mild and transition metal-free reaction conditions consolidate this method's potential for synthesizing pharmaceutically relevant compounds and precursors of supramolecular nanostructured materials.

In the present research, multicomponent one-pot green synthesis of sulfonyl-substituted 2-amino-4H-pyran derivatives through the reaction of aromatic aldehyde, cyclic ketone and phenyl (or methyl) sulfonyl acetonitrile was developed. This multicomponent reaction distinguishes by employing a less expensive and non-toxic sodium L-ascorbate as a catalyst which represents a simple, efficient and environmentally benign route to obtain sulfonyl substituted 2-amino-4H-pyran derivatives in moderate to good yields. The major advantages of the present work are high efficiency, short reaction time, use of cheap, safe and stable catalyst system as well as green solvent and mild reaction condition. Herein, we introduce an efficient and green multicomponent one-pot protocol for the synthesis of sulfonyl-substituted 2-amino-4H-pyran derivatives in 80% EtOH using sodium L-ascorbate (NaAsc) as catalyst.

magnified imageAn efficient and convenient method for the preparation of pyrimidine and quinazoline derivatives by the one‐pot reaction of aromatic aldehydes, cyclic ketones and guanidine carbonate, in the presence of sodium hydroxide under solvent‐free condition was reported. This method has the advantages of excellent yields, mild reaction conditions, easy work‐up, and being environmentally friendly over the existing procedures. J. Heterocyclic Chem., (2009).

From aldehydes or cyclic ketones, diazoalkanes, and tertiary phosphanes, olefins may be prepared according to Equation (a) with MTO as catalyst. In particular, diazoacetates and -malonates (R2, R3H, CO2,Et, or 2 × CO2 Me) can be transformed into olefins with aliphatic and aromatic aldehydes (R1iPr, trans-PhCHCH, Ph, 4-NO2C6H4, etc.). Readily accessible starting materials, easy handling, mild reaction conditions, and good yields characterize the new synthesis method. (R′Ph, 3-C6H4SO3Na, nBu.)

A practical and efficient procedure for the one‐pot multicomponent couping of aryl aldehydes, 2‐naphthol and cyclic 1,3‐dicarbonyl compounds using perchloric acid adsorbed on silica gel (HClO4‐SiO2) as a highly efficient, inexpensive, convenient, reusable heterogeneous catalyst under solvent‐free conditions has been developed. Various biologically important 12‐aryl‐8,9,10,12‐tetrahydrobenzo[a]xanthen‐11‐one derivatives have been efficiently synthesized in high to excellent yields. The present approach offers several advantages such as shorter reaction times, simple work‐up, excellent yields, low cost, and mild reaction conditions. Furthermore, the catalyst can be recovered simply and reused without appreciable loss of its catalytic activity.

ZnCl2 Enabled Synthesis of Highly Crystalline and Emissive Carbon Dots with Exceptional Capability to Generate O2⋅–

Efficient hydro-finishing of polyalfaolefin based lubricants under mild reaction condition using Pd on ligands decorated halloysite

Analysis of nitrogen fixation by a catalyst capable of transforming N2, CO2 and CH4 into amino acids under mild reactions conditions