Diverse bispiro-3,4-dihydropyrans consisting of oxindole moieties with three contiguous chiral centers and vicinal quaternary stereocenters were synthesized with very good yields of up to 92% and excellent enantioselectivity of up to 99% ee by using a proline-derived thiourea organocatalyst. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Venkitasamy Kesavan

Department Of Biotechnology

Manjunatha Vishwanath

Poopathy Vinayagam

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

Asian Journal of Organic Chemistry

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 catalytic efficiency of a bifunctional chiral thiourea derived from l-proline was evaluated in the asymmetric direct vinylogous Michael reaction of α,α-dicyanoolefins to β-nitrostyrenes with an electron-releasing or electron-withdrawing substituent in various positions. The corresponding adducts were isolated in good yields, with excellent diastereo- (>99%) and enantioselectivity (up to 95%). The Michael adducts were further functionalized to achieve the synthesis of polycyclic fused pyrrolidines with three contiguous stereocenters in good enantioselectivities. © Georg Thieme Verlag Stuttgart, New York.

Fulltext

Synthesis (Germany)

Construction of Polycyclic Fused Pyrrolidines with Three Contiguous Stereocenters via Michael Addition of Vinylmalononitriles to Nitrostyrenes Using l -Proline-Derived Thiourea

Michael/hemiketalization of 2-hydroxy-1,4-naphthoquinone to oxindole ketoester was studied using a series of chiral bifunctional organocatalysts. Good yields (up to 91%) and excellent enantioselectivities (up to 98%) were achieved by using a proline derived thiourea catalyst. This method provides an elegant synthetic route to access oxindole containing naphthoquinone derivatives. © 2016 The Royal Society of Chemistry.

RSC Advances

Organocatalytic construction of spirooxindole naphthoquinones through Michael/hemiketalization using l-proline derived bifunctional thiourea

Sequential vinylogous Michael addition-cyclization reactions of vinyl malononitriles with isatylidene malononitrile were accomplished using l-proline derived bifunctional thiourea. Cyclohexylidine malononitrile afforded exclusively the single diastereomer with good to excellent enantioselectivity (up to 99% ee) for diverse oxindole spirocyclohexene derivatives. Tetralone derived α,α-dicyano alkene was also employed to access spirocyclic oxindole scaffolds with an excellent level of stereoselectivity (up to 99% ee). © The Royal Society of Chemistry.

Enantioselective assembly of functionalized carbocyclic spirooxindoles using an L-proline derived thiourea organocatalyst

Reaction-Based Mechanistic Investigations of Asymmetric Hetero-Diels-Alder Reactions of Enones with Isatins Catalyzed by Amine-Based Three-Component Catalyst Systems

Chemical Reviews

Stereocontrolled Formation of Several Carbon–Carbon Bonds in Acyclic Systems

Angewandte Chemie International Edition

Stereoselective Organocatalytic Synthesis of Oxindoles with Adjacent Tetrasubstituted Stereocenters

Asymmetric Organocatalytic Assembly of Oxindoles Fused with Spiro-3,4-dihydropyrans with Three Contiguous Stereocenters Consisting of Vicinal Quaternary Centers

Journal	Data powered by TypesetAsian Journal of Organic Chemistry
Publisher	Data powered by TypesetWiley-VCH Verlag
ISSN	21935807
Open Access	No