PUBLICATION

Publications:

2026

Mechanochemical Control of Stereospecific Strain Release in Chiral Spiroaziridine Oxindoles with Alkyl Amines
Ankita Biswas, Ananda Shankar Mondal, Ayan Chatterjee, Subhas Chandra Debnath, and Saumen Hajra*
https://doi.org/10.1021/acs.orglett.6c03017

Cover page, Org. Lett. Aug 21, 2026, Volume 28, Issue 33, Pages 10421-10652

Base-Controlled Dual Pd Catalysis Enabling Tunable Tandem
C(sp3)-H Cyclopalladation-Annulation and 6-endo-trig Heck
Cyclization
Upamanyu Das, Pritam Roy, Saumen Hajra*
Org. Lett. (2026) 28 (33): 10427–10432

Cr(III)-Salen Catalyzed Enantioselective C3-Aryloxylation of Spiroepoxy Oxindoles

Ananda Shankar Mondal, Arindam Jana, Ayan Chatterjee, Kumaresh Ghosh, Saumen Hajra*
J. Org. Chem. 2026, 91, 7, 2708–2723

2025

Asymmetric Synthesis of 3,3′-Pyrrolidonyl Spirooxindole-5′-Carboxylic Ester from l-Tryptophan

Atanu Hazra, Dhananjoy Maity, Suhas S. Bhosale, Saumen Hajra*
Synthesis 2025; 57(02): 488-494

PROCESS FOR THE PREPARATION OF (HETERO) POLYARENES, NAPHTHALENE- AND TETRALIN LIGNANS
Prof. Saumen Hajra, Upamanyu Das, and Pritam Roy
Indian Patent No.: 573750 (Granted)

Regio- and Stereospecific Nucleophilic C3-Azidation of Spiroaziridine Oxindoles: Synthesis of Enantiopure 3-Azido- and 3-Triazole-2-Oxindoles
Ananda Shankar Mondal, Ankita Biswas, Arindam Jana, Kumaresh Ghosh and Saumen Hajra*
J. Org. Chem. 2025, 90, 36, 12558–12572

2024

A Concise Asymmetric Total Synthesis of (+)-8-Epigrosheimin via Catalyst-Free Tandem Allylboration–Lactonization
Dhananjoy Maity, Ramkrishna Maity, Manoranjan Jana, Saumen Hajra*
Synlett 2024; 35(20): 2542-2546

2023

Sequential Hydroperoxylation and Amberlyst-15 Catalyzed Hock-Type Rearrangement of Spiroepoxy/Spiroaziridine Oxindoles for the Synthesis of 2-Hydroxybenzo[b][1,4]oxazin-3(4H)-ones
Saleh, S. A.; Mondal, A. S.: Senapati, S.: Hajra, S.*
Asian J. Org. Chem., 2023

Organocatalytic aldol approach for the protecting group-free asymmetric synthesis of (7R′)-parabenzlactone, (−)-hinokinin, (−)-yatein, (−)-bursehernin, (−)-pluviatolide, (+)-isostegane and allied lignans
Bera, M.; Sen, B.; Garai, S.; Hajra, S.*
Org. Biomol. Chem., 2023,21, 8749-8756

Asymmetric total synthesis of (+)-propolisbenzofuran B
Sen, B.; Bera, M.; Hajra, S.*
Chem. Commun., 2023,59, 8254-8257

Catalytic Enantioselective Synthesis of 4-Amino-5-aryltetrahydro-1H-benzo[c]azepines by an Aminoarylation Reaction
Akhtar, S. M. S.; Hajra, S.*
Synlett, 2023, 34, 645-650

2022

Regio- and Stereospecific Desulfinylative Chlorination of Spiroaziridine Oxindoles at Spiro-Center for Formal [3+2]-Cycloaddition with CS2: Sequential One-Pot Synthesis of (−)-Spirobrassinin
Biswas, A.; Hajra, S.*
Adv. Synth. Catal., 2022, 364, 17, 3035-3042

Asymmetric Total Synthesis of Eupalinilide E, a Promoter of Human HSPC Expansion
Maity, R.; Hajra, S.*
Org. Lett. 2022, 24, 26, 4745–4749

Selective C3-Allylation and Formal [3 + 2]-Annulation of Spiro-Aziridine Oxindoles: Synthesis of 5′-Substituted Spiro[pyrrolidine-3,3′-oxindoles] and Coerulescine
Saleh, S. A.; Hazra, A.; Singh, M. S.; Hajra, S.*
J. Org. Chem. 2022, 87, 13, 8656–8671

Cover page, J. Org. Chem. March 18, 2022, Volume 87, Issue 6, Pages 3885-4488

Stereochemistry of the Benzylidene -Butyrolactone Dictates the Reductive Heck Cyclization Mode in Asymmetric Synthesis of Aryltetralin Lignans: A Detail Experimental and Theoretical Study
Sen, B.; Roy, S.; Garai, S.; Sayan Roy, S.; Anoop, A.; Hajra, S.*
J. Org. Chem. 2022, 87, 3910–3921

Regioselective Hydroperoxylation of Aziridines and Epoxides Only with Aqueous Hydrogen Peroxide
Saleh, S. A.; Hazra, A.; Hajra, S.*
Adv. Synth. Catal., 2022, 364, 391-404

Asymmetric aminoarylation for the synthesis of trans-3-amino-4-aryltetrahydroquinolines: An access to aza-analogue of dihydrexidine
Akhtar, S. M. S.; Bar, S.; Hajra, S.*
Tetrahedron, 2022,103, 132257

2021

Sequential one-pot synthesis of N-sulfonyl spiroaziridine oxindoles from spiroepoxy oxindoles
Biswas, A.; Saleh, S. A.; Hazra, A.; Debnath, S. C.; Hajra, S.*
Org. Biomol. Chem., 2021, 19, 5624-5631

2020

Efficient chemical fixation and defixation cycle of carbon dioxide under ambient conditions
Hajra, S.,* Biswas, A.
Sci Rep 2020, 10, 15825

Co(III)salen Catalyzed Enantioselective C3‐Indolylation of Spiro‐epoxyoxindoles and Its Mechanistic Studies
Hajra, S.* Roy, S.; Mondal, A. S.
Adv. Synth. Catal., 2020, 362(23), 5475-5484

Chromatography-free “two-pots” asymmetric total synthesis of (+)-sesamin and (+)-aschantin
Hajra, S.* Garai, S.; Sen, B.
Tetrahedron. 2020, 76, 131483

Catalyst-Free Stereocontrolled Formal [3 + 2]-Cycloaddition of CO2 for the Synthesis of Enantiopure Spiro[indoline-3,5′-oxazolidine]-2,2′-diones under Aqueous and Ambient Conditions
Hajra, S.* Biswas, A.
Org. Lett. 2020, 22(13), 4990-4994

Organocatalytic Enantioselective Conjugate Addition of Nitromethane to Benzylidene-2-Benzoyl Acetate: Asymmetric Synthesis of ABT – 627, an Endothelin Receptor Antagonist
Hajra, S.* Aziz, S. M.; Jana, B.; Hazra, S.
Frontier in Chemistry 2020, 8, 135

Feedback Inhibition in Chemical Catalysis Leads the Dynamic Kinetic to Kinetic Resolution in C3-Indolylation of Spiro-epoxyoxindoles
Hajra, S.* Roy, S.
Org. Lett. 2020, 22(4), 1458-1463

2019

Aqueous tert-Butyl Hydroperoxide Mediated Regioselective Ring-Opening Reactions of Spiro-aziridine/-epoxy Oxindoles: Synthesis of 3-Peroxy-3-substituted Oxindoles and Their Acid-Mediated Rearrangement
Hajra, S.* Hazra, A.; Saleh, S. A.; Mondal, A. S.
Org. Lett. 2019, 21(24), 10154-10158

The Organocatalytic Enantioselective Mukaiyama-Mannich Reaction of Isatin-Derived Ketimines for the Synthesis of Oxindolyl-β3,3-Amino Acid Esters
Hajra, S.*Laskar, S.; Jana, B.
Chem. Eur. J. 2019, 25, 1-7

The One pot asymmetric synthesis of 3,3′-pyrrolidonyl spiroxindoles via regio- and stereoselective domino reaction
Hajra, S.* Bhosale, S. S.; Hazra, A.; Kanaujia, N.
Org. Biomol. Chem. 2019, 17, 8140-8148

Controlling the regioselectivity of the ring opening of spiro-epoxyoxindole for efficient synthesis of C(3)–N(1′)-bisindole and C(3)–N(1′)-diindolylmethane
Hajra, S.*, Maity, S.; Roy, S.; Das, D.
Org. Biomol. Chem. 2019, 17, 7747-7759

One Pot Synthesis of Enantiopure Spiro[3,4-dihydrobenzo[b][1,4]oxazine-2,3'-oxindole] via Regio- and Stereoselective Tandem Ring Opening/Cyclization of Spiroaziridine Oxindoles with Bromophenols
Hajra, S.* Hazra, A.; Saleh, S. A.
J. Org. Chem. 2019, 84, 10412-10421

Organocatalytic Domino Reaction of Spiroaziridine oxindoles and Malononitrile for the Enantiopure Synthesis of Spiro[dihydropyrrole-3,3′-oxindoles]
Hajra, S.* Saleh, S. A.; Hazra, A.; Singh, M. S.
J. Org. Chem. 2019, 84, 8194-8201

Reagent Controlled Reversal of Regioselectivity in Nucleophilic Fluorination of Spiro-epoxyoxindole: Synthesis of 3-Fluoro-3-hydroxymethyloxindole and 3-Aryl-3-fluoromethyloxindole
Hajra, S.* Roy, S.; Maity, S.; Chatterjee, S.
J. Org. Chem. 2019, 84, 2252-2260

Brønsted Acid Promoted Regioselective C-3 Arylation and Heteroarylation of Spiro-epoxyoxindoles for the Construction of All Carbon Quaternary Centres: A Detailed Study
Hajra, S.* Maity, S.; Roy, S.; Maity, S.; Samanta. S.
Eur. J. Org. Chem. 2019, 5, 969-987

2018

Stereocontrolled Nucleophilic Fluorination at the Tertiary sp3-Carbon Center for Enantiopure Synthesis of 3-Fluorooxindoles
Hajra, S.* Hazra, A.; Mandal. P.
Org. Lett. 2018, 20 (20), 6471–6475

Domino Corey–Chaykovsky Reaction for One-Pot Access to Spirocyclopropyl Oxindoles
Hajra, S.* Roy, S.; Saleh. S. A.
Org. Lett. 2018, 20 (15), 4540–4544

Catalyst-Free Ring Opening of Spiroaziridine Oxindoles by Heteronucleophiles: An Approach to the Synthesis of Enantiopure 3-Substituted Oxindoles
Hajra, S.* Roy, S.S.; Biswas, A.; Saleh, S. A.
J. Org. Chem. 2018, 83(7), 3633-3644

2017

Catalytic Enantioselective Synthesis of (−)-Podophyllotoxin
Hajra, S.* Garai, S.; Hazra, S.
Org.Lett. 2017, 19 (24), 6530–6533

Asymmetric acetate-Mannich reaction of chiral isatin derived ketimines and its applications
Hajra, S.* Bhosale. S. S.; Hazra, A.
Org. Biomol. Chem. 2017,15, 9217-9225

Quinine-Based Trifunctional Organocatalyst for Tandem Aza-Henry Reaction-Cyclization: Asymmetric Synthesis of Spiroxindole-Pyrrolidine/Piperidines
Hajra, S.* Jana, B.
Org.Lett. 2017,19(18), 4778

Catalyst-Free “On-Water” Regio- and Stereospecific Ring-Opening of Spiroaziridine Oxindole: Enantiopure Synthesis of Unsymmetrical 3,3′-Bisindoles
Hajra, S.; Singha Roy, S.; Aziz, S. M.; Das, D.
Org. Lett. 2017, 19, 4082

Unified total synthesis of (+)-chinensiolide B and (+)-8-epigrosheimin
Hajra, S.,*Acharyya, S, Mandal, A., Maity, R.
Org. Biomol. Chem. 2017, 15, 6401-6410

Reversal of selectivity in C3-Allylation and Formal [3+2] Cycloaddition of Spiro-epoxyoxindole: Unified Synthesis of Spiro-furanooxindole,(±)N-Methylcoerulescine, (±)Physovenine, and 3a-Allylhexahydropyrrolo[2,3-b]indole
Hajra, S.; Roy, S.; Maity, S.
Org. Lett. 2017, 19, 1998-2001

2016

Regioselective Friedel-Crafts Reaction of Benzenoid Arenes and Spiroepoxyoxindole at Spiro-Centre: Efficient Synthesis of Benzofuroindolines and 2H-Spiro[benzo-furan]-3,3¢-oxindoles
Hajra, S.; Maity, S.; Roy, S.
Adv. Synth. Catal. 2016, 358, 2300-2306

Dihydrochelerythrine and its derivatives: Synthesis and their application as potential G-quadruplex DNA stabilizing agents
Malhotra, R.; Rarhi, C.; Diveshkumar, K. V.; Barik, R.; D’cunha, R.; Dhar, P.; Kundu *, M.; Chattopadhyay, S.; Roy, S.; Basu, S.; Pradeepkumar*, P. I.; Hajra*, S.
Biorg. Med. Chem. 2016, 24, 2887

Synthesis of Chiral Spiro-Aziridine Oxindoles via Aza-Corey-Chaykovsky Reaction of Isatin Derived N-tert-Butanesulfinyl Ketimines
Hajra, S.; Aziz, S. M.; Jana, B.; Mahish, P.; Das, D.
Org. Lett. 2016, 18, 532

2015

Efficient Synthesis of 3,3′-Mixed Bisindoles via Lewis Acid Catalyzed Reaction of Spiro- epoxyoxindoles and Indoles
Hajra, S. ; Maity, S.; Maity, R.
Org. Lett. 2015, 17, 3430

Enantio-pure synthesis of dihydrobenzo[1,4]-oxazine-3-carboxylic acids and approach to benzoxazinyl oxazolidinones
alhotra, R.; Dey, T. K.;. Basu,* S.; Hajra,* S.
Org. Biomol. Chem. 2015, 13, 3211

Work at IIT Kharagpur

"Asymmetric synthesis towards doxanthrine, a dopamine D1 full agonist" Malhotra, R.; Ghosh, A.; Dutta, S.; Dey, T. K.; Basu,* S.; Hajra,* S. RSC Advances 2014, 4, 48344-48347.[link]
"Efficient asymmetric synthesis of N-protected-ß-aryloxyamino acids via regioselective ring opening of serine sulfamidate carboxylic acid" Malhotra, R.; Dey, T. K.;. Dutta, S.; S.; Basu,* S.; Hajra,* S. Org. Biomol. Chem., 2014, 12, 6507 - 6515.[link]
"Catalytic asymmetric aminolactonization of 1,2-disubstitued alkenoic acid esters: Efficient construction of aminolactones with all-carbon quaternary stereo-centre" Hajra, S.; Akhtar, S. M. S.; Aziz, S. M. Chem. Commun. 2014, 50, 6913 – 6916.[link]
"A diastereoselective route to 2,5-diaryl-3,4-disubstituted tetrahydro-furan lignans: protection free synthesis of (+)-galbelgin and (+)-galbacin" Hazra, S.; Hajra, S. RSC Advances 2013, 3, 22834.[link]
"Protecting Group Directed Cyclization: Asymmetric Synthesis of Both cis- and trans-Dihydrexidine from a Common Precursor" Malhotra, R.; Chakrabarti, S; Dey, T. K.;. Dutta, S.; Alapati, K. B.; Roy, S.; Dutta, S.; Basu,* S.; Hajra,* S. Tetrahedron 2013, 69, 8994. [link]
"Organocatalytic enantioselective conjugate addition of nitromethane to alkylidenemalonates: Asymmetric synthesis of pyrrolidine-3-carboxylic acid derivatives" Hajra, S.; Aziz, S-M.; Maji, R. RSC Advances 2013, 3, 10185. [link]
"Asymmetric aldol approach to dibenzylbutyrolactone lignans: Synthesis of (─)-(7′S)-hydroxymatairesinol and (─)-(7′S)-hydroxyarctigenin" Hajra, S.; Mandal, A.; Hazra, S. Tetrahedron Lett. 2013, 54, 2171. [link]
"Divergent asymmetric synthesis of hexahydrobenzophenanthridine dopamine D1 agonists, A-86929 and dihydrexidine" Malhotra, R.; Chakrabarti, S; Dey, T. K.;. Ghosh, A.; Ghosh, R.; Dutta, S.; . Roy, S.; Dutta, S.; Basu,* S.; Hajra,* S. Tetrahedron: Asymm. 2013, 24, 278. [link]
"Conjugate Addition of Indoles and Pyrroles to Dihydronitronaphthalenes in Water: Synthesis of 3,4-Fused Tetrahydro-β-carbolines" Malhotra, R.; Ghosh, R.; Dey, T. K.; Chakrabarti, S.; Ghosh, A.; Dutta, S.; .; Asijaa, S.; Roy, S.; Dutta, S.; Basu,* S.; Hajra,* S. Eur. J. Org. Chem. 2013, 772. [link]
"Rhodium-Catalyzed Enantioselective Conjugate Addition of Arylboronic Acids to Dihydronitronaphthalenes" Hajra, S.; Ghosh, R.; Chakrabarti, S.; Ghosh, A.; Dutta, S.; Dey, T. K.; Malhotra, R.; Asijaa, S.; Roy, S.; Dutta, S.; Basu, S. Adv. Synth. Catal. 2012, 354, 2433. (Highlighted in Synfacts) [link]
"A rapid room temperature chemical route for the synthesis of graphene: metal-mediated reduction of graphene oxide" Dey, R. S.; Hajra, S.; Sahu, R. K.; Raj, C. R.; Panigrahi, M. K. Chem. Commun. 2012, 48, 1787. [link]
"Catalytic and enantioselective synthesis of dopamine D1 antagonist, ecopipam" Hajra, S.; Bar, S. Tetrahedron: Asymm. 2012, 23, 151. (Highlighted in Synfacts). [link]
"Asymmetric synthesis of the dopamine D1 agonist, dihydrexidne from D-serine" Malhotra, R.; Ghosh, A.; Ghosh, R.; Chakrabarti, S.; Dutta, S.; Dey, T. K.; Roy, S.; Basu,* S.; Hajra,* S. Tetrahedron: Asymm. 2011, 22, 1522. [link]
"Catalytic Enantioselective Aziridoarylation of Aryl Cinnamyl Ethers toward Synthesis of trans-3-Amino-4-arylchromans" Hajra, S.; Sinha, D. J. Org. Chem. 2011, 76, 7334.[link]
"Asymmetric synthesis of the dopamine D1 agonist, dihydrexidne" Hajra, S.; Bar, S. Tetrahedron: Asymm. 2011, 22, 775. [link]
"Catalytic enantioselective synthesis of A-86929, a dopamine D1 Agonist" Hajra, S.; Bar, S. Chem. Commun. 2011, 47, 3981-3982. [link]
"Asymmetric epoxidation f cinnamic acid derivatives by in situ generated dioxiranes of chloroacetones: Scope and limitations" Hajra, S.; Bhowmick, M. Tetrahedron: Asymm. 2010, 21, 2223. [link]
"Asymmetric Syntheses of (–)-Enterolactone and (7¢R)-7¢-Hydroxyenterolactone via Organo-catalyzed Aldol Reaction" Hajra, S.; Giri, A. K.; Hazra, S. J. Org. Chem. 2009, 74, 7978.[link]
"A Catalytic and Enantioselective Synthesis of trans-2- Amino-1-aryltetralins" Hajra, S.; Maji, B.; Mal, D. Adv. Synth. Catal. 2009, 351, 859. [link]
"Organocatalytic and Enantioselective Synthesis of b-(Hydroxyalkyl) -g-Butyrolactones" Hajra, S.; Giri, A. K. J. Org. Chem. 2008, 73, 3935.[link]
"Stereoselective One-Pot Synthesis of Oxazolines" Hajra, S.; Bar, S.; Sinha, D.; Maji, B. J. Org. Chem. 2008, 73, 4320.[link]
"Concise Syntheses of (+)- and (-)-Methylenolactocins and Phaseolinic Acids" Hajra, S.; Giri, A. K.; Karmakar, A. and Hazra, S. Tetrahedran Lett. 2008, 49, 3625. [link]
"A One-Pot Stereoselective Synthesis of trans-1-Amino-2-Aryltetralins from 2-Arylethyl Styrenes" Hajra, S.; Maji, B.; Sinha, D.; Bar, S. Tetrahedran Lett. 2008, 49, 4057. [link]
"Design and Synthesis of Chiral N-Chloro-imidodicarbonates: Application to Asymmetric Chlorination of Silylenol Ethers." Hajra, S. Bhowmick, M.; Maji, B. and Sinha, D. J. Org. Chem. 2007, 72, 4872.[link]
"Samarium triflate catalyzed and halogen-promoted Friedel-Crafts Alkylation with Alkenes" Hajra, S, Maji, B. and Bar, S. Org. Lett. 2007, 9, 2783. [link]
"Asymmetric aldol reactions under normal and inverse addition modes of reagents" Hajra, S.; Giri, A. K.; Karmakar, A.; Khatua, S. Chem. Comm. 2007, 2408. [link]
"Metal Triflates Catalyzed Reactions of Alkenes, NBS, Nitriles and TMSN3: Synthesis of 1,5-Disubsituted Tetrazoles" Hajra, S.; Sinha, D. and Bhowmick, M. J. Org. Chem. 2007, 72, 1852.[link]
"Highly Regio- and Stereoselective Asymmetric Bromoazidation of Chiral a,b-Unsaturated Carboxylic Acid Derivatives: Scope and Limitations" Hajra, S.; Bhowmick, M.; Sinha, D. J. Org. Chem. 2006, 71, 9237.[link]
"Metal triflate catalyzed highly regio- and stereoselective 1,2-bromoazidation of alkenes using NBS and TMSN3 as the bromine and azide sources" Hajra, S.; Sinha, D.; Bhowmick, M. Tetrahedran Lett. 2006, 47, 7017. [link]
"Stereoselective synthesis of (-)-chloramphenicol and (-)-thiomphenicol" Hajra, S.; Karmakar, A.; Maji, T. and Medda, A. Tetrahedron 2006, 62, 8959. [link]
"Silver (I)-promoted asymmetric O-methylhalohydrin reaction of chiral α,β-unsaturated carboxylic acid derivatives: Enantioselective synthesis of N-protected syn-b-methoxy-a-amino acids" Hajra, S.; Karmakar, A.; and Bhowmick, M. Tetrahedron Asymm. 2006, 17, 210. [link]
"Lewis Acid Catalyzed Intramolecular Halo-Arylation of Tethered alkenes using NXS as a Halonium Source: A General Method for the Synthesis of Chromanons, Chromans, Quinolones, Tetrahydroquinolines and Tetralins" Hajra, S.; Maji, B. and Karmakar, A. Tetrahedran Lett. 2005, 46, 8599. [link]
"Lewis acid catalyzed asymmetric halohydrin reactions of chiral a,b-unsaturated carboxylic acid derivatives with N-halosuccinimide (NXS) as the halogen source" Hajra, S.; Bhowmick, M. and Karmakar, A. Tetrahedron Lett. 2005, 46, 3073. [link]
"Silver (I)-promoted asymmetric halohydrin reaction of chiral N-enoyl-2-oxazolidinones: Scope and limitations" Hajra, S.; Karmakar, A.; and Bhowmick, M. Tetrahedron 2005, 61, 2279. [link]
"Asymmetric O-methylhalohydrin reaction of chiral N-enoyl-2-oxazolidinones: Synthesis of N-protected syn-b-methoxyphenylalanine, an unusual amino acid component of cyclomarins" Hajra, S.; Karmakar, A. Tetrahedron Lett. 2004, 45, 3185. [link]

Selected Post-Doctoral and Ph.D. Publication

"Free-Radical-Mediated Conjugate Additions. Enantioselective Synthesis of Butyrolactone Natural Products: (-)-Enterolactone, (-)-Arctigenin, (-)-Isoarctigenin, (-)-Nephrosteranic Acid, and (-)-RoccellaricAcid." Sibi, M. P.; Liu, P.; Ji, J.; Hajra, S. and Chen, J. J. Org. Chem. 2002, 67, 1738.[link]
"A Highly Chemoselective Oxidation of Alcohols to Carbonyl Products with Iodosobenzene Diacetate Mediated by Chromium(III)(salen) Complexes: Synthetic and Mechanistic Aspects." Adam, W.; Hajra, S.; Herderich, M. and Saha-Möller, C. R. Org. Lett. 2000, 2, 2773. [link]
"Synthesis of Silicon-Containing Alanines." Sibi, M. P.; Harris, B.; Shay, J. J. and Hajra, S. Tetrahedron 1998, 54, 7221. [link]
"The Intermolecular b-Coupling of Cyclic Enones with Activated Alkenes and Alkynes: Unexpectedb-Alkoxy Elimination from a 4-Alkoxy-2-Alkyl-1-Hydroxy-Cyclopentyl Radical." Pandey, G.; Ghorai, M. K. and Hajra, S. Tetrahedron Lett. 1998, 39, 8341. [link]
"A New Strategy for the Construction of Carbo- and Oxycycles by Intramolecular Reductive Coupling of a,b-Unsaturated Esters" Pandey, G.; Ghorai M. K. and Hajra S. Tetrahedron Lett. 1998, 39, 1831.[link]
"Visible-Light Initied Photosensitized Electron Transfer (PET) Cyclization of Aldehydes and Ketones to Tethered a,b-Unsaturated Esters: Stereoselective Synthesis of Optically Pure C- Furanoside" Pandey, G.; Hajra, S.; Ghorai, M. K. and Ravi Kumar, K. J. Org. Chem. 1997, 62, 5966.[link]
"Designing of a Photosystem to Harvest Visible-Light to Electrons by Sequential Electron Transfer Processes: Reversing the Reactivity Profiles of a,b-Unsaturated Ketones as Carbon Radical Precursor by One Electron Reductive b-Activation" Pandey, G.; Hajra, S.; Ghorai, M. K. and Ravi Kumar, K. J. Am. Chem. Soc. 1997, 119, 8777. [link]
"Designing of a Photosystem to Harvest Visible-Light to Electrons: Photosensitized one Electron Redox Reactions in Organic Synthesis" Pandey, G.; Hajra, S. and Ghorai, M. K. Pure & Appl. Chem. 1996, 68, 653.[link]
"Visible-Light Initiated Photosensitized Electron Transfer (PET) Reductive b-Activation of a,b-Unsaturated Ketones for Radical Cyclization: A New Concept in Promoting Radical Reactions" Pandey, G.; Hajra, S. and Ghorai, M. K. Tetrahedron Lett. 1994, 35, 7837. [link]
"A Novel Photosystem for Harvesting Visible-Light to Drive Photoinduced Electron Transfer (PET) Reductions: b-Activation of a,b-Unsaturated Ketones for Radical Cyclization " Pandey, G. and Hajra, S. Angew. Chem. Int. Ed. (Engl.), 1994, 33, 1169. [link]