Isoxazole group directed Rh(III)-catalyzed alkynylation using TIPS-EBX.

A highly effective isoxazole directed C-H alkynylation has been developed. Rhodium(III) catalyzed direct di-(and/or mono) alkynylation using a hypervalent iodine reagent (TIPS-EBX) is reported. The reaction proceeds with a wide substrate scope under benign conditions.

Intramolecular Hydroarylation of Arenes via Imidazole-Directed C-H Activation in Aqueous Methanol Using Rhodium(III) as the Catalyst and Mechanistic Study.

A mild and greener approach for intramolecular regioselective hydroarylation is described for the efficient and elegant preparation of a number of dihydrobenzofurans and dihydrobenzo[]thiophenes using imidazole as a directing group and Rh(III) as a catalyst. Moreover, the protocol may be extended to the formation of indoline and chromane derivatives. Deuterium scrambling experiments and characterization of isolated rhodacycle intermediate were explored to understand the mechanism in a better way.

An iron(ii)-based metalloradical system for intramolecular amination of C(sp)-H and C(sp)-H bonds: synthetic applications and mechanistic studies.

A catalytic system for intramolecular C(sp)-H and C(sp)-H amination of substituted tetrazolopyridines has been successfully developed. The amination reactions are developed using an iron-porphyrin based catalytic system. It has been demonstrated that the same iron-porphyrin based catalytic system efficiently activates both the C(sp)-H and C(sp)-H bonds of the tetrazole as well as azide-featuring substrates with a high level of regioselectivity.

Partial purification and characterization of a thermophilic and alkali-stable laccase of isolate KU4 with dye-decolorization efficiency.

Production of an extracellular thermophilic and alkali stable laccase from isolate KU4 was reported for the first time, both in submerged fermentation (SmF, highest 1590 U/mL) and solid state fermentation (SSF, highest 2014.21 U/mL) using agro-industrial residues. The laccase was partially purified to 7.

Additive-Free, Pd-Catalyzed 3-Amino-1-methyl-1-pyridin-2-one-Directed C(sp)-H Arylation and Methylation in Water.

Small molecules containing a 2-pyridone unit received much attention due to their significance in medicinal chemistry. In this regard, development of novel methodologies via metal-catalyzed carbon-carbon bond formation by chelation-assisted C-H activation will be an attractive method to achieve therapeutically important 2-pyridone analogues and arylated acid synthons. We report our studies on a Pd(II)-catalyzed coupling reaction between methyl, aryl, heteroaryl iodides, and sp carbons both at β- and γ-positions using 3-amino-1-methyl-1-pyridin-2-one as an efficient, built-in bidentate ,-directing group (DG) toward the synthesis of pyridone derivatives.

Chemoenzymatic reduction of citreorosein and its implications on aloe-emodin and rugulosin C (bio)synthesis.

A chemoenzymatic reduction of citreorosein by the NADPH-dependent polyhydroxyanthracene reductase from Cochliobolus lunatus or MdpC from Aspergillus nidulans in the presence of NaSO gave access to putative biosynthetic intermediates, (R)-3,8,9,10-tetrahydroxy-6-(hydroxymethyl)-3,4-dihydroanthracene-1(2H)-one and its oxidized form, (R)-3,4-dihydrocitreorosein. Herein, we discuss the implications of these results towards the (bio)synthesis of aloe-emodin and (+)-rugulosin C in fungi.

Stereoselective Peptide Modifications via β-C(sp)-H Arylations.

Palladium-catalyzed stereoselective β-arylations of phenylalanine, proline- and pipecolinic acid-containing peptides are a versatile tool for peptide modifications. The reactions proceed without epimerization of stereogenic centers in the peptide chain. If suitable functionalized aryl iodides are introduced, subsequent cross coupling reactions can be used for further modifications.

Pd(OAc)2-catalyzed dehydrogenative C-H activation: An expedient synthesis of uracil-annulated β-carbolinones.

An intramolecular dehydrogenative C-H activation enabled an efficient synthesis of an uracil-annulated β-carbolinone ring system. The reaction is simple, efficient and high yielding (85-92%).

Advances in metal-free heterocycle-based columnar liquid crystals.

Liquid crystals are ordered soft materials formed by self-organized molecules and can potentially be used as new functional materials for electron-, ion- or molecular-transport; optical; and bio-active materials. In particular, the columnar liquid crystals are promising candidates used in various optical and electronic devices. For this purpose, design and synthesis of unconventional materials are essential.