Bromo- or Methoxy-Group-Promoted Umpolung Electron Transfer Enabled, Visible-Light-Mediated Synthesis of 2-Substituted Indole-3-glyoxylates.

A visible-light-mediated radical tandem cyclization of ortho-isocyano-α-bromo cinnamates to 2-substituted indole-3-glyoxylates is achieved by formation of both C-C/C-S and C-O bonds. The reaction proceeds through a hitherto unprecedented bromine- or methoxy-group-promoted umpolung back electron transfer from an α-carbonyl radical to the photocatalyst. This method allows preparation of diverse 2-arylated or 2-thioarylated indole-3-glyoxylates.

Unravelling the secret of seed-based gels in water: the nanoscale 3D network formation.

Chia (Salvia hispanica) and basil (Ocimum basilicum) seeds have the intrinsic ability to form a hydrogel concomitant with moisture-retention, slow releasing capability and proposed health benefits such as curbing diabetes and obesity by delaying digestion process. However, the underlying mode of gelation at nanoscopic level is not clearly explained or explored. The present study elucidates and corroborates the hypothesis that the gelling behavior of such seeds is due to their nanoscale 3D-network formation.

Visible-Light-Accelerated Copper(II)-Catalyzed Regio- and Chemoselective Oxo-Azidation of Vinyl Arenes.

The visible-light-accelerated oxo-azidation of vinyl arenes with trimethylsilylazide and molecular oxygen as stoichiometric oxidant was achieved. In contrast to photocatalysts based on iridium, ruthenium, or organic dyes, [Cu(dap) ]Cl or [Cu(dap)Cl ] were found to be unique for this transformation, which is attributed to their ability to interact with the substrates through ligand exchange and rebound mechanisms. Cu is proposed as the catalytically active species, which upon coordinating azide will undergo light-accelerated homolysis to form Cu and azide radicals.

Sugar based amphiphiles: easily accessible and efficient crude oil spill thickening agents.

In this work, we demonstrate the use of biomass for the catalytic production of phase-selective gelators (PSGs) as a cost-effective, environmentally benign and ideal method for crude oil spill remediation, as well as execute the study exclusively in crude oil. The use of PSGs has recently provided great promise relative to that of their traditional counterparts. However, the use of PSGs with crude oil is much more complicated due to its complex composition.

Stoichiometric sensing to opt between gelation and crystallization.

A new class of organogelators having a cyclohexane-1a,3a-diol motif capable of congealing non-polar liquids was developed. These gelators underwent crystallization at low concentration and gelation above the critical gelation concentration (CGC) in the same solvent. The crystals and gel fibers were analyzed by single crystal XRD and PXRD respectively, which revealed their different modes of assembly.

Total syntheses of five uvacalols: structural validation of uvacalol A, uvacalol B and uvacalol C and disproval of the structures of uvacalol E and uvacalol G.

Uvacalols are novel carbasugars belonging to the family of C7-cyclitols, and are isolated from the roots of the medicinal plant, Uvaria calamistrata. In this study, we report the first syntheses of five uvacalols starting from a cheap and easily available chiral pool starting material, D-mannitol, in their optically pure form. D-Mannitol was converted to the alkene 2 through a series of regioselective and chemoselective transformations by following our previously reported strategies.

Chemoselective alcoholysis/acetolysis of trans-ketals over cis-ketals and its application in the total synthesis of the cellular second messenger, D-myo-inositol-1,4,5-trisphosphate.

The involvement of natural phosphoinositols in various cellular signalling processes and the use of synthetic inositol derivatives in catalysis, supramolecular chemistry, natural product synthesis etc. gave momentum to myo-inositol chemistry. The presence of six secondary hydroxyl groups necessitates efficient protection-deprotection strategies for the synthesis of inositol derivatives.

Regioselectivity among six secondary hydroxyl groups: selective acylation of the least reactive hydroxyl groups of inositol.

We report the first, general and selective acylation of the least reactive hydroxyl group among six secondary hydroxyl groups of inositol in high yield, using very cheap and easy-to-make H(2)SO(4)-silica as the catalyst, providing easy access to bioactive molecules.

Soft optical devices from self-healing gels formed by oil and sugar-based organogelators.

Sweet and low: two sugar-based supergelators can congeal oils to produce highly transparent gels with glass-like refractive indices showing low UV transmittance and high visible transmittance and remarkable self-healing properties. This unique blend of properties can be exploited to make soft optical devices from these gels.