Three-component strategy toward 5-membered heterocycles from isocyanide dibromides

A three-component strategy starting from isocyanides allows a straightforward synthesis of five-membered ring heterocycles. New cascades were developed involving the addition of a nitrogenated nucleophile-an azide or a tetrazole-on isocyanide dibromides, an electrocyclization, and a Suzuki coupling, which afford new accesses to tetrazole and triazole scaffolds.     

Xanthate based radical cascade toward multicomponent formation of pyrrolopyrimidines

A short sequential synthesis of pyrrolidino- pyridines and pyrimidines illustrates the potential of combining Ugi-Smiles couplings with radical tin-free processes.     

A tandem oxidative dearomatization/intramolecular Diels-Alder reaction: a short and efficient entry into tricyclic system of maoecrystal V

A short and efficient route to tricyclic ring system containing bridged bicyclo[2.2.2]octanone annulated with a lactone ring present in the maoecrystal is described. In-situ generation of spiroepoxycyclohexa-2,4-dienone and intramolecular cycloaddition are the key features of our approach.     

Medium energy ion irradiation of Ge surface – search for a better understanding of the surface nano‐patterning

We report the morphological changes on Ge surfaces upon 50 keV Ar⁺ and 100 keV Kr⁺ beam irradiation at 60° angle of incidence. The Ge surfaces having three different amorphous–crystalline (a/c) interfaces achieved by the pre‐irradiation of 50 keV Ar⁺ beam at 0°, 30° and 60° with a constant fluence of 5 × 10¹⁶ ions/cm² were further processed by the same beam at higher fluences viz. 3 × 10¹⁷, 5 × 10¹⁷, 7 × 10¹⁷ and 9 × 10¹⁷ ions/cm² to understand the mechanism of nano‐scale surface patterning. The Kr⁺ beam irradiation was carried out only on three fresh Ge surfaces with ion fluences of 3 × 10¹⁷, 5 × 10¹⁷ and 9 × 10¹⁷ ions/cm² to compare the influence of projectile mass on surface patterning. Irrespective of the depth of a/c interface, the nanoscale surface patterning was completely missing on Ge surface with Ar⁺ beam irradiation. However, the surface patterning was evidenced upon Kr⁺ beam irradiation with similar ion fluences. The wavelength and the amplitude of the ripples were found to increase with increasing ion fluence. In the paper, the mass redistribution at a/c interface, the incompressible solid flow through amorphous layer, the angular distribution of sputtering/backscattering yields and the generation of non‐uniform stress across the amorphous layer are discussed, particularly in analogy with low energy experiments, to get better understanding of the mechanism of nanoscale surface patterning by the ion beams. Copyright © 2016 John Wiley & Sons, Ltd.     

Fused Heterocycles: Synthesis and Antitubercular Activity of Novel 6‐Substituted‐2‐(4‐methyl‐2‐substituted phenylthiazol‐5‐yl)H‐imidazo[1,2‐a]pyridine

A series of 6‐substituted‐2‐(4‐methyl‐2‐substituted phenylthiazol‐5‐yl)H‐imidazo[1,2‐a]pyridine derivatives 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l is described. The antitubercular activity of the synthesized compounds was determined against Mycobacterium smegmatis MC² 155 strain. From the activity result, it was found that the phenyl or 4‐fluorophenyl group at 2 position of thiazole nucleus and bromo substituent at 6 position of imidazo[1,2‐a]pyridine showed good antitubercular activity.     

Polyethylene glycol(PEG) mediated expeditious synthetic route to 1,3-oxazine derivatives

Various 1,3-oxazine derivatives were synthesized in high yields,within shorter reaction times using PEG-400 as a safer medium/ mediator.This synthetic route is exceedingly easy and avoids the use of acid/base catalysts.     

Self-healing property of optical ring lattice

We generate experimentally optical ring lattice structures which are the superposition of two coaxial Laguerre-Gaussian modes with common waist position and waist parameter. Although these structures are not diffraction-free, they show self-healing property. This self-reconstruction of the ring lattice can be understood by looking into the transverse energy flow at different z planes. The experimental results are verified by the numerical simulations.     

B-Chlorodialkylboranes for the enolboration of 3,3,3-trifluoropropionates

The increased acidity of the α-protons of 3,3,3-trifluoropropionates was exploited to achieve the enolboration of these esters using dialkylchloroboranes.