A new class of bifunctional tertiary amine thiourea was synthesized from l-proline. The reported thiourea is amenable to steric and electronic modifications at the stereogenic center bearing a thiourea moiety. Excellent enantioselectivity was obtained in the Michael addition of 2,4-pentanedione to various nitro olefins using the new organocatalyst. The construction of contiguous stereocenters via the Michael reaction of substituted 1,3-dicarbonyls to nitro olefins was also carried out with very good yield, enantioselectivity, and diastereoselectivity. © 2014 Elsevier Ltd. All rights reserved.

Venkitasamy Kesavan

Department Of Biotechnology

Poopathy Vinayagam

Manjunatha Vishwanath

alkene

carbonyl derivative

proline

thiourea

article

asymmetric catalysis

catalyst

controlled study

diastereoselectivity

Enantioselectivity

Michael addition

ORGANOCATALYST

priority journal

stereochemistry

synthesis

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

Tetrahedron Asymmetry

A new synthetic strategy to construct spirooxindole-naphthopyran scaffold has been demonstrated via Friedel-Crafts type/hemiketalization of oxindole α-ketoester with 2-naphthol. Under the established reaction condition, quaternary chiral center at C3-position of oxindole has been created with very good asymmetric induction up to 98 % for a broad range of substrates. DFT calculations, which account for the stereochemical outcome, were performed. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

ChemCatChem

Organocatalytic Enantioselective Assembly of Spirooxindole-naphthopyrans through Tandem Friedel-Crafts Type/Hemiketalization

Erratum: New class of bifunctional thioureas from l-proline: Highly enantioselective Michael addition of 1,3-dicarbonyls to nitroolefins (Tetrahedron Asymmetry (2014) 25 (568-577))

A new class of highly stable O,N,N,O-tetradentate bioxazoline ligands were synthesized from l-tartaric acid. Exploration of those ligands in Pd-catalyzed asymmetric allylic alkylation yielded alkylated product up to 96% ee. Necessity of additional chelation to obtain high enantioselectivity was also demonstrated. Structural modifications of this ligand might result in identification of a novel privileged chiral ligand from an inexpensive chiral pool. © 2013 Elsevier Ltd. All rights reserved.

Tetrahedron

Novel O,N,N,O-tetradentate ligand from tartaric acid

Novel C 2-symmetric chiral bioxazolines were synthesized in good yields by the fusion of optically active acids with a tartaric acid derivative. Complexes of these products with copper(II) acetate monohydrate were found to be excellent catalysts for the Henry reaction, giving various nitro alcohols in very good yields and up to 84% enantiomeric excess. Although only five-membered chelation is possible with these ligands, they give better enantioselectivities than other bioxazoline ligands that undergo similar coordination. © Georg Thieme Verlag Stuttgart · New York.

Synthesis (Germany)

Asymmetric henry reaction catalyzed by novel chiral bioxazolines from tartaric acid

Advanced Synthesis & Catalysis

A Polystyrene-Supported, Highly Recyclable Squaramide Organocatalyst for the Enantioselective Michael Addition of 1,3-Dicarbonyl Compounds to β-Nitrostyrenes

Tetrahedron Letters

Highly efficient and enantioselective Michael addition of acetylacetone to nitroolefins catalyzed by chiral bifunctional organocatalyst bearing multiple hydrogen-bonding donors

Organic Letters

Catalytic Asymmetric Formal [4 + 1] Annulation Leading to Optically Activecis-IsoxazolineN-Oxides

New class of bifunctional thioureas from l-proline: Highly enantioselective Michael addition of 1,3-dicarbonyls to nitroolefins

Journal	Data powered by TypesetTetrahedron Asymmetry
Publisher	Data powered by TypesetElsevier Ltd
ISSN	09574166
Open Access	No