A new bifunctional squaramide organocatalyst derived from l-proline mediated the first enantioselective synthesis of dihydrospiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives in excellent enantioselectivity by reacting pyrazolones with isatylidine β,γ-unsaturated α-ketoester. This new catalyst outperformed widely used thioureas and squaramides in inducing enantioselectivity. © 2016 American Chemical Society.

Venkitasamy Kesavan

Department Of Biotechnology

Nandarapu Kumarswamyreddy

amide

indole derivative

indoline

proline

pyran derivative

pyrazole derivative

PYRAZOLONE DERIVATIVE

spiro compound

thiourea

chemical structure

chemistry

Stereoisomerism

synthesis

Amides

Indoles

Molecular Structure

Pyrans

Pyrazoles

PYRAZOLONES

Spiro compounds

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Organic Letters

3-Alkynyl-3-OBoc oxindoles underwent Cu(II) mediated Friedel-Crafts alkylation with indoles and phenols to yield of structurally diverse 3-alkynyl-3-indole/phenol-oxindole derivatives. The synthetic application of alkylated phenol derivatives were further demonstrated to biologically important new class of chromene fused spirooxindoles through intramolecular metal-free iodocyclization under mild reaction conditions with broad substrate scope in very good yields. © 2018 Elsevier Ltd

Tetrahedron Letters

Efficient synthesis of highly functionalized indole and phenol containing 3,3′-disubstituted oxindoles and chromene fused spirooxindoles

The first highly diastereo- and enantioselective synthesis of armeniaspirol analogues was achieved using L-proline derived bifunctional squaramide which outperformed commonly used organocatalysts. Excellent yield (up to 99%) with diastereoselectivity (up to 99:1) and enantioselectivity (up to 99%) were obtained for a wide range of substrates. © 2017 American Chemical Society.

Journal of Organic Chemistry

Diastereo- and Enantioselective Synthesis of 2,2-Disubstituted Benzofuran-3-one Bearing Adjacent Quaternary and Tertiary Stereocenters

Palladium(ii)-catalyzed C3-allylation of 3-ethynyl-3-OBoc oxindole derivatives was achieved for the first time to access highly functionalized 3-allyl-3-ethynyl substituted oxindole derivatives for a broad range of substrates in very good yields (up to 94%). The synthetic applications of the allylated products were explored by synthesizing five and six membered carbocyclic spirooxindoles in moderate to very good diastereoselectivities. © The Royal Society of Chemistry.

Fulltext

RSC Advances

Assembly of 3-allyl-3-ethynyl-oxindole motifs via palladium(ii)-catalyzed quaternary allylation of 3-ethynyl-3-OBoc-oxindoles

3-Allyl-3-hydroxyoxindoles were synthesized in very good enantio- (up to 97% ee) and diastereoselectivities (dr up to 7.6:1) with contiguous quaternary and tertiary stereogenic centers by employing tartrate derived bi(oxazoline) in Pd-catalyzed allylation of 3-OBoc-oxindole. Synthetic utility of 3-allyl-3-hydroxyoxindole was demonstrated by synthesizing a highly substituted spiro(oxindole-3,2′-tetrahydrofuran) derivative in good yield and stereoselectivity. © 2015 American Chemical Society.

Palladium catalyzed asymmetric allylation of 3-OBoc-Oxindoles: An efficient synthesis of 3-Allyl-3-hydroxyoxindoles

Medicinal Chemistry Research

A comprehensive review on bioactive fused heterocycles as purine-utilizing enzymes inhibitors

European Journal of Medicinal Chemistry

Pyrazoloquinazolines: Synthetic strategies and bioactivities

Catalyst-free domino reaction in water/ethanol: an efficient, regio- and chemoselective one-pot multi-component synthesis of pyranopyrazole derivatives

Enantioselective Synthesis of Dihydrospiro[indoline-3,4′-pyrano[2,3-c]pyrazole] Derivatives via Michael/Hemiketalization Reaction

Journal	Data powered by TypesetOrganic Letters
Publisher	Data powered by TypesetAmerican Chemical Society
ISSN	15237060
Open Access	No