Barbier allylation-Prins reaction of PEG-bound aldehydes—soluble polymer-supported synthesis of 2,4,6-trisubstituted tetrahydropyrans

PEG-bound aldehydes undergo zinc-mediated Barbier allylation to form homoallylic alcohols, which on further reaction with various aldehydes in the presence of BF₃·Et₂O through a Prins cyclization afford 4-hydroxytetrahydropyrans and 4-fluorotetrahydropyrans.     

Design,synthesis and spectroscopic and crystallographic characterisation of novel functionalized pyrazole derivatives: biological evaluation for their cytotoxic,angiogenic and antioxidant activities

Research on Chemical Intermediates - The current study presents the synthesis of functionalized pyrazoles (18–29) through 3?+?2 annulation reaction of ethyl...     

Structural,spectral, and theoretical investigations of 5-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid

Research on Chemical Intermediates - The present research work has focused on combined experimental and theoretical studies of one of the biologically important pyrazole-4-carboxylic acid...     

DABCO-Promoted Efficient and Convenient Synthesis of Benzofurans

An efficient and convenient synthesis of benzofurans has been described from phenacyl halides and o-hydroxy benzaldehyde in the presence of DABCO. The procedure is applicable for a variety of phenacyl halides and provide a variety of benzofurans. DABCO act as a base and as well as nucleophile.     

Brookhart's Acid-Catalyzed Switchable Regioselective N-Alkylation of Arylamines/Heterocyclic Amines with Cyclopropylcarbinols by Temperature Regulation

An unprecedented, Brookhart's acid-catalyzed temperature-switchable regioselective divergent approach for N-alkylation of arylamines and heterocyclic amines by utilising cyclopropylcarbinols is presented herein. The reaction offers N-alkylated cyclopropyl derivatives and homoallyl amines by employing 2.5 mol% catalyst loading at different temperatures in excellent regioselectivity and yields. This method has shown to be relevant with a wide range of cyclopropylcarbinols, including aliphatic ones. Several control experiments and spectroscopic studies have been performed to gain insight into the reaction mechanism. Further, the synthetic utility of the protocol has also been described.     

Synthesis,Biological Evaluation,and Lipinski Analysis of New Hybrids Containning 1,2,3-Triazoles and Dihydropyrimidinone Scaffolds

Russian Journal of General Chemistry - A series novel dihydropyrimidinone (DHPM) containing 1,2,3-triazole moiety have been designed and synthesized using Cu(I) catalysed azide-alkyne cycloaddition...     

Mechanical and thermo‐mechanical studies of double networks based on thermoplastic elastomers

A new approach to prepare and characterize double network elastomeric systems was investigated. A styrene‐ethylene‐co‐butylene‐styrene (SEBS) triblock copolymer system containing physical crosslinks was used to achieve a double network by additional crosslinking using ultra‐violet (UV) light. An ethylene–propylene–diene monomer (EPDM) terpolymer system containing chemical crosslinks was used to achieve a conventional double network using UV crosslinking. Properties from conventional monotonic tensile tests, dynamic mechanical analysis, and thermomechanical properties were investigated. These double network elastomers show a transition between competitive and collaborative behavior in their mechanical properties and lower coefficients of thermal expansion arising from a competition of the networks. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 778–789, 2010     

CP violation in the B→Kℓ<Superscript>+</Superscript>ℓ<Superscript>-</Superscript> decay

Standard model (SM) CP asymmetries in B→Kℓ⁺ℓ^- are expected to be very small. This feature could help in the understanding of new physics scenarios which predict the existence of CP odd phases in various Wilson coefficients. In this paper we have analyzed the B→Kℓ⁺ℓ^- decay in scenarios beyond the SM where the Wilson coefficients have new CP odd phases. The sensitivity of the CP asymmetries on these new weak phases is discussed. PACS 13.20.He; 12.60.-i; 13.88.+e     

Non-paraxial theory of self-defocusing/focusing of a laser pulse in a multiple-ionizing gas

The self-focusing of a laser pulse through a tunnel ionizing gas (helium) has been studied in both non-relativistic and relativistic regimes, relaxing the near-axis approximation. In the non-relativistic regime, the laser pulse produces multiple ionization of the gas and faces strong defocusing due to the steep radial density gradient caused by the same. The uneven defocusing of paraxial and marginal rays leads to a beam acquiring a ring shaped intensity distribution. In the relativistic regime, the laser pulse produces fully ionized plasma within a few wave periods, subsequently the relativistic mass effect and the ponderomotive force induced electron cavitation cause periodic self-focusing. PACS 52.38.Hb; 42.65.Jx