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The ligand-enabled development of ortho and meta C–H borylation of aromatic aldehydes is reported. It was envisaged that while ortho borylation could be achieved using tert-butylamine as the traceless protecting/directing group, meta borylation proceeds via an electrostatic interaction and a secondary interaction between the ligand of the catalyst and the substrate. These ligand–substrate electrostatic interactions and secondary B–N interactions provide an unprecedented controlling factor for meta-selective C–H activation/borylation.

Xanthones are one of the biggest classes of compounds in natural product chemistry. A number of xanthones have been isolated from natural sources of higher plants, fungi, ferns, and lichens. They have gradually risen to great importance because of their medicinal properties. This review focuses on the types, isolation, characterization, biological applications, and biosynthesis of naturally occurring xanthones isolated so far. Different physicochemical and instrumental methods such as liquid-solid and liquid-liquid extraction, TLC, flash chromatography, column chromatography, IR, 1H NMR and 13C NMR spectroscopy, GLC, HPLC, GC, and LCMS have been widely used for isolation and structural elucidation of xanthones. Hepatoprotective, anticarcinogenic, antileprosy, antimalarial, antioxidant, anticholinergic, mutagenicity, radioprotective, immunomodulatory, antibone resorption, antiparasitic, neuraminidase inhibitory, anticomplement, antibacterial, antifungal, algicidal, anti-HIV, cardioprotective, antitumoral, antidiabetes, antihyperlipidemic, antiatherogenic, anti-inflammatory, antiulcer, antidiabetic, hypolipidemic, analgesic, antiasthmatic, antihistaminic, antiamoebic, diuretic, antidiarrheal, larvicidal, and ovicidal activities have been reported for natural occurring xanthones. To a certain extent, this review provides necessary foundation for further research and development of new medicines.

In this highlight, two aspects of chiral metal–organic frameworks, in particular synthetic approaches to achieve chiral MOFs and their applications, have been discussed. There has been considerable research advancement towards the synthesis of chiral MOFs by direct or indirect methods. More recently, homochiral MOFs have been exploited for valued applications such as asymmetric catalysis, enantioselective separation and recognition processes. Each part is subdivided with regard to the issues focused on and provides seminal as well as recent reports from the literature.

A new procedure for the mild, practical, and scalable Diels—Alder reaction of tropones with arynes is reported.

Chemotherapy is a major therapeutic approach for the treatment of localized and metastasized cancers. Whereas potent chemotherapeutic agents seem promising in the test tube, clinical trials often fail due to unfavorable pharmacokinetics, poor delivery, low local concentrations, and limited accumulation in the target cell. The pathophysiology of the tumor vasculature and stromal compartment presents a major obstacle to effective delivery of agents to solid tumors. Poor perfusion of the tumor, arterio-venous shunting, necrotic and hypoxic areas, as well as a high interstitial fluid pressure work against favorable drug uptake. Thus, targeted drug delivery using long-circulating particulate drug carriers such as hydrogels of controlled size (

The one-pot multicomponent reaction of xylofuranosyl dialdoses (I) with β-keto compounds (II) and anilines (III) affords the pentofuranosyldihydropyridines (IV) in good yields.

The yeast lipase Candida cylindracea (CCL) and porcine pancreatic lipase (PPL) have been used for regioselective deacylation of peracetylated benzopyrones, diphenylpropenones and acetophenones for the first time. The deacylation study on different classes of polyphenols has revealed that the presence of carbonyl group attached to the aromatic ring is needed by the lipases to exhibit regioselectivity towards hydrolysis of acetoxyl groups. The acetoxyl groups at positions other than the one at ortho position to the carbonyl group get selectively hydrolysed by PPL in orgnnic solvents. The trnnsesterification reactions using triflouroethylbutyrate (TFEB), catalysed by PPL and CCL on some polyols in dry organic solvents were also performed. It was found that the primary hydroxyl is acylated. In D-panthenol, the oxidised dextrorotatory form of which is a major constituent of vitamin B-complex, the primary hydroxyl group at the far end of the asymmetric carbon atom gets exclusively acylated. This work should be of importance in the synthesis of building blocks of biologically active natural products which may provide structural leads to anti AIDS and anticancer agents.

Several compounds from Piper species bearing methylenedioxyphenyl moieties are reported for the first time to effectively inhibit the rat liver microsome-mediated aflatoxin B1-DNA binding in vitro. From the preliminary results obtained, a structure-activity relationship is proposed.

A new synthesis of the title compound, C 8 H 6 Cl 2 O 4 , is described. The molecule has a mirror plane and the six-membered carbon ring assumes a slight boat conformation. The ring substituents are arranged in an alternating 'up and down' pattern with respect to the best plane through the ring C atoms.

Porcine pancreatic lipase (PPL) has been immobilized in microemulsion-based gels (MBGs). Highly selective and efficient deacylation of di/trihydric phenolic perpropanoates has been observed on incubating them with immobilized PPL. These reactions can find general utility in Synthetic Organic Chemistry.

Enantioselection effected by commercially available hydrolytic enzymes reported in recent years from our own laboratory and those published by other groups is described. The discussion is confined to enantioselection in symmetric diols, amino acids and benzopyran derivatives only. The paper describes a variety of substrates accepted by these hydrolytic enzymes to produce compounds in high enantiomeric excess which can be used as chiral building blocks for the synthesis of compounds of pharmaceutical and synthetic interest.

1,4-Disubstituted-1,2,3-triazoles (3–27) have been synthesized by [3+2] cycloaddition of different 2-(azidomethyl)-dihydronaptho(benzo)furans (2a, 2b, 2c and 2d) with different alkynes. All the compounds were screened for antitubercular activity against Mycobacterium tuberculosis H37Rv. Compounds 2a, 7, 9, 12 and 14 exhibited antitubercular activities with MIC ranging from 12.5 to 3.12 μg/ml.

A simple and efficient chemoselective alkylation of phenols in polyfunctional aromatic compounds with different alkyl halides in the presence of K2CO3/TBAB is reported. The method is successful with various hydroxy aromatic acids or oximes possessing other functional groups.

The synthesis and X-ray crystal structures of the first resorcin[4]arene cavitands by ring-closing metathesis reaction are described.

A 100% selectivity with an order of magnitude rate enhancement is obtained in the synthesis of phenolic ethers when synergistic combination of solid–liquid phase transfer catalysis and low energy microwave irradiation (MISL‐PTC) is employed. As against conventional microwave heating with 600 W power input, the current work demonstrates that a low input of 40 W leads to remarkable enhancement in rates without any destruction of the catalyst.

Regioselective transesterifications and hydrolysis of peracylated sophorolipid (SL) derivatives catalyzed by lipases was investigated. This study is the first evaluation of the lipase-catalyzed reactions on the non-lactonic SL derivatives. Four lipases, namely from porcine pancreas (PPL, Type II), Candida rugosa (AYS, TypeVII), Pseudomonas cepacia (PS-30), and Candida antarctica (Novozym 435, carrier fixed lipase fraction B) were used in anhydrous THF or in phosphate buffer (pH=7.4, 0.2 M). It was confirmed from the detailed spectral analysis of the products that transesterification failed to furnish any free hydroxyls on the sophorose ring. Instead, transesterification took place on the methyl ester located at the carboxylic end of the 17-hydroxyoctadecenoic acid chain attached to the C-1′ position of the sophorose ring. It is proposed that in absence of the lactonic structural motif, the binding of the peracylated non-lactonic SLs in the lipase binding pocket takes place such that the carboxyl group of the octadecenoic acid, not the sophorose sugar, is preferentially accessible to the active site.