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A cascade double aryne insertion reaction was developed to generate a library of diarylmethane scaffolds. Additionally, chromone products were observed in presence of an electronegative atom at the ortho position of aryne.

Cyclic and acyclic vinyl substituted β-keto/enol carbonyl substrates, on reaction with arynes, result in differentially substituted naphthyl carbocycles, hitherto difficult to synthesize with existing protocols. While the substitutions on the arynes have no role, the ring size of the cyclic β-keto/enol esters has a profound influence on the product formation.

An efficient and highly diastereoselective synthesis of CF3-dihydrobenzofurans by the reaction of in situ-generated CF3-oQMs in the presence of a base with sulphur ylides is put forward. The generality of the present developed method was well studied with diverse substrates to access the corresponding products in excellent yields. The highly reactive CF3-oQM has been utilized first time for the annulation reaction.

An efficient Mn-catalyzed cascade azide radical addition/cyclization/oxygen insertion reaction of alkyne-tethered cyclohexadienones with TMSN3 under mild conditions is reported. This domino reaction presents good diastereoselectivity generating bicyclic azido alcohol scaffolds which can be transformed into useful building blocks in organic synthesis for medicinal chemistry.

The organocatalytic Diels–Alder reaction in non-conventional solvent (PEG-400) has yielded cycloaddition products with diastereoselectivities hitherto not reported in detail using classical reaction conditions.

(±)-Asenapine, sold in the market as Saphris/Sycrest for the treatment of bipolar disorders, is synthesized in an optically pure form involving an Ireland–Claisen rearrangement as the key step. This approach allows access to all diastereomers.

The most abundantly available hexose sugar, d-glucose has been converted to protected 4-amino(2'amino-4'-hydroxy phenyl)-3,5-dihydroxy-2-methyl-6-oxo hexanoic acid (protected ADMOA, 3), the unusual amino acid present in marine natural product solomonamide A in gram quantities involving easy to operate chemical transformations.

The source or inspiration of many marketed drugs can be traced back to natural product research. However, the chemical structure of natural products covers a wide spectrum from very simple to complex. With more complex structures it is often desirable to simplify the molecule whilst retaining the desired biological activity. This approach seeks to identify the structural unit or pharmacophore responsible for the desired activity. Such pharmacophores have been the start point for a wide range of lead generation and optimisation programmes using techniques such as Biology Oriented Synthesis, Diversity Oriented Synthesis, Diverted Total Synthesis, and Fragment Based Drug Discovery. This review discusses the literature precedence of simplification strategies in four areas of natural product research: proteins, polysaccharides, nucleic acids, and compounds isolated from natural product extracts, and their impact on identifying therapeutic products.

The syntheses of two novel peptidomimetic triazole-based organocatalysts that work for the asymmetric conjugate addition of cyclohexanone to nitroolefins are described. The catalysts worked with very low loading (0.5 mol%) in the absence of any additives to provide high diastereo- and enantio-selectivities.

Residue based control of specific helical folding is explored in hybrid peptide oligomers consisting of alternating L-Ala and cis-beta-furanoid sugar amino acid (FSAA) residues as building blocks; two series of these hybrid oligomers are designed, synthesized and extensively characterized by using NMR, CD, FT-IR and MD simulation studies; results show the co-existence of left-handed 11- and 14/15-helical conformations in these short oligomers of Boc-(alpha/beta) and Boc-(beta/alpha) series.

The design, synthesis and characterization of a new class of peptide nanotubes, self-assembled from cyclic homo- and hetero-beta-peptides based on cis-furanoid sugar amino acid and beta-hGly residues are described; these results represent the expansion of the conformational pool of cis beta-sugar amino acids in the design of peptide nanotubes.

Bromoacetals derived from 5,6-dideoxy-1,2-O-isopropylidene-α-D-xylo-hex-5-ynofuranose (9) undergo facile free radical cyclization leading to the formation of olefinic acetals which are chemially manipulated to introduce either of the chiralities at C-5 of α-D-hexofuranose.

The total synthesis of 5-epi-Torrubiellutin C is described in a fully stereocontrolled manner and linear sequence involving high yielding steps. The synthetic strategy involves the dicyclohexylboron chloride mediated Paterson's aldol protocol, Horner–Emmons olefination, TiCl4 mediated syn-aldol reaction and ring closing metathesis (RCM) as the key steps. Furthermore, the resultant epimer was evaluated for cytotoxicity against DU145 (prostate), MCF-7 (breast) and A549 (lung) cancer cell lines, and the results showed that the 5-epi-Torrubiellutin C is as good as the natural product in bioassays.

The oligomers of constrained cis-exo-beta-norbornene amino acid were synthesised and characterised by extensive NMR, CD, IR and MD studies. The results showed the formation of both right and left handed consecutive 6-membered hydrogen-bonded strands for [2S,3R] and [2R,3S] enantiomers, respectively.

PEG (400) has been used as a recyclable and rapid reaction medium for the asymmetric dihydroxylation of olefins; Sharpless ligand is efficiently recovered and recycled with good enantioselectivity.