Raghavan B. Sunoj
Associate Professor of Chemistry
and Convener for High Performance Computing@IITB
Contact Information
Department of Chemistry Indian Powai, Mumbai 400076 Phone : 22-2576-7173 Fax : 22-2576-7152 e-mail : sunoj[at]chem.iitb.ac.in |
|
Field of Specialization : Theoretical
Organic Chemistry and Computational Chemistry
Research Interests
Understanding chemical reactions in greater detail requires different information such as structural parameters, orbital interactions, energetic details, effect of media and other external perturbations. One of my basic research goals is to answer questions on stereoselectivity, catalysis, stability and reactivity of organic molecules. I make use of standard ab initio and density functional theory calculations as powerful tools to address problems in these situations. Often times, such questions are rooted directly on experimental observations. Applications of quantum chemical calculations to systems of immediate practical significance are further more interesting due to their nearly direct relationship with experiments.
Questions range from reactivities of interesting small
molecules to conformational issues in large bio-molecular systems. Research methods
include applications of standard methods for locating precise transition states
of complex organic reactions. The approach requires both chemical intuition as
well as in-depth understanding of the reaction. Computational methods are also applied
in understanding molecular vibrations, electronic transitions as well as
nuclear magnetic resonance (nmr) chemical shifts.
Quantification of electronic effects such as hyperconjugation are carried out using the natural bond orbital analysis
(NBO) methods. Interesting bonding situations are addressed using
Atoms-in-Molecule formalism. Conformational studies on bio molecules as well as
other fluxional systems are studied by a combination of
1. STEREOSELECTIVity
in organic reactions
Electronic structure calculations on kinetically controlled reactions could give valuable insights on stereoselectivity. While there could be methodology dependent issues (in terms of accuracy), stereoselectivity problems can effectively be addressed using relative energy calculations of diastereomeric transition states. Currently, we are working on a number of organic reactions where the origins of selectivity are not well understood. Some of these reactions fall in the domain of emerging area of organocatalysis.
2. ROLE
of Explicit solvents in organic reactions
We are also interested in examining the energetics associated with solvent assisted reactions. Both explicit and implicit solvent models are studied for standard organic reactions.
3. Other areas of Interest
* Computational thermochemistry of interesting molecules. * Studies on reactive intermediates such as carbenes and carbynes. * Intramolecular weak interactions in organic molecules. * Cycloaddition chemistry with emphasis on regioselectivity issues. * Electronic structure calculations on transition metal complexes.
ACADEMIC
BACKGROUND
|
Degree |
University/Institute |
Year |
|
M. Sc. |
|
1996 |
|
Ph. D. |
Indian |
2001* |
*Advisor :
Professor J. Chandrasekhar
PROFESSIONAL
EXPERIENCE
|
Employment |
University/Institute |
Year |
|
Post doctoral research associate |
The |
2001-2003 |
|
Assistant Professor |
IIT |
2003 |
|
Associate Professor |
IIT |
2007 |
PUBLICATIONS (Selected list from a total of 69 publications)
|
Moorthy, J. N.; Monahan, S. L.; Sunoj, R. B.; Chandrasekhar, J.; Bohne, C. Modulation of Lifetimes and
Diastereomeric Discrimination in Triplet-Excited Substituted Butan-1,
4-diones through Intramolecular Charge-Transfer Quenching. J. Am. Chem. Soc.1999,
121, 3093 - 3103.
Laxminarasimhan, P.; Sunoj, R. B.;
Chandrasekhar, J.; Ramamurthy, V. 'Cation-pi
Interaction Controlled Selective Geometric Photoisomerization of
Diphenylcyclopropane’. J. Am. Chem. Soc. 2000,
122, 4815.
Pavlos, C. M.; Cohen, A. D.; D'Sa, R. A.; Sunoj,
R. B.; Wasylenko, W. A.; Kapur, P.; Relyea, H. A.; Kumar, N. A.; Hadad,
C. M.; Toscano, J. P. Photochemistry of
1-(N,N-Diethylamino)diazen-1-ium-1,2-diolate: An Experimental and
Computational Investigation. J. Am. Chem. Soc. 2003,
125, 14934.
Sarkar, B.; Patra, S.; Fiedler, J.; Sunoj, R. B.;
Janardanan, D.; Mobin, S. M.; Niemeyer, M.; Lahiri, G. K.; Kaim, W.
Theoretical and Experimental Evidence for a New Kind of Spin-Coupled Singlet
Species: Isomeric Mixed-Valent Complexes Bridged by a Radical Anion Ligand. Angew. Chemie, Int. Ed. 2005, 44,
5655.
Roy, D.; Sunoj, R. B.
Quantification of Intramolecular Nonbonding Interactions in
Organochalcogens. J. Phys. Chem. A 2006, 110, 5942.
Patil, M. P.; Sunoj, R. B. Density
Functional Theory and Atoms-in Molecule Study on the Role of Two-electron
Stabilizing Interactions in Retro Diels-Alder Reaction of Cycloadducts
Derived from Substituted Cyclopentadiene and p-Benzoquinone. Org. Biomol.
Chem. A 2006, 4, 3923.
Janardanan, D.; Sunoj, R. B. 'Density Functional
Theory Investigations on Sulfur Ylide Promoted Cyclopropanation Reactions:
Insights on Mechanism and Diastereoselection Issues. J.
Org. Chem. 2007, 72, 331.
Shinisha, C. B.; Sunoj, R. B. 'Bicyclic
Proline Analogues as Organocatalysts for Stereoselective Aldol Reactions: An
In-Silico Density Functional Theory Study' Org. Biomol. Chem. 2007,
5, 1287.
Janardanan, D.; Sunoj, R. B. Computational Investigations on the General Reaction Profile and Diastereoselection in Sulfur Ylide Promoted Aziridinations. Chem. Eur. J. 2007,
13, 4805.
Patil, M.P.; Sunoj, R. B. Insights on Co-catalyst Promoted Enamine Formation between Dimethylamine and Propanal through Ab-initio and Density Functional Theory Study. J. Org. Chem. 2007,
72, 8202.
Roy .D.; Sunoj, R. B.'Ab initio and Density Functional Theory Evidence on the Rate-Limiting Step in the Morita-Baylis-Hillman Reaction' Org. Lett. 2007,
9, 4873.
Lahiri, S.; Yadav, S.; Banerjee, S.; Patil, M. P.; Sunoj, R. B.'Face Slective Diels-Alder Reaction between Unsymmetrical Cyclohexadienes and Asymmetric trans-Dienophile: An Experimental and Computational Investigation' J. Org. Chem. 2008,
73, 435. Sarkar, B.; Patra, S.; Fiedler, J.; Janardanan, D.; Sunoj, R. B.; Lahiri, G. K.; Kaim, W. 'Mixed-Valent Metals Bridged by a Radical Ligand: Fact, or Fiction Based on Structure-Oxidation State Correlations' J. Am. Chem. Soc. 2008,
130, 3532. Roy, D.; Patel, C.; Liebman, J. F.; Sunoj, R. B.; 'Probing Intramolecular Interactions in Arylselenides Using a Property
Descriptor Based Approach' J. Phys. Chem. A. 2008,
112, 8797-8803. Patil, M. P; Sunoj, R. B.; 'The Role of Non-innocent Solvent Molecules in Organocatalyzed Asymmetric Michael Reaction' Chem. Eur. J. 2008, 14, 10472. Roy, D.; Sunoj, R. B.; 'Water-Catalysis in Morita-Baylis-Hillman Reaction: A Mechanistic Perspective' Chem. Eur. J. 2008, 14, 10530. Shinisha, C. B; Sunoj, R. B.; 'Unraveling High Precision Stereocontrol in a Triple Cascade Organocatalytic Reaction' Org. Biomol. Chem. 2008, 6, 3921. :[featured as the front cover page of issue no 21, 2008] Janardanan, D.; Sunoj, R. B.; 'Enantio and Diastereoselectivities in Chiral Sulfur Ylide Promoted Asymmetric Aziridination Reactions' J. Org. Chem. 2008, 73, 8163.
Patil, M. P.; Sunoj, R. B.; 'On the Relative Preference of Enamine/Iminium Pathways in Organocatalytic Michael Addition of Aldehydes to a,b-Unsaturated Ketones' Chem. Asian J. 2009, 4, 714.
Shinisha, C. B.; Sunoj, R. B.; 'On the Origin of Kinetic Resolution of Cyclohexane 1,2-diols Through Stereoselective Acylation by Chiral Tetrapeptides' Org. Lett. 2009, 11 , 3242.
Roy, D.; Patel, C.; Sunoj, R. B.; 'Mechanistic Insights and the Role of Co-catalysts in Aza-Morita-Baylis-Hillman and Morita-Baylis-Hillman Reaction' J. Org. Chem. 2009, 74, 6936.
Rajeev, R.; Sunoj, R. B.; 'On the Origin of Reversible Hydrogen Activation by Phosphino-Boranes' Chem. Eur. J. 2009, 15, 12846.
Roy, D.; Sunoj, R. B.; 'Ni, Pd, or Pt Catalyzed Ethylene Dimerization: A Mechanistic Description of the Catalytic Cycle and the Active Species' Org. Bimol. Chem. 2010, 8 , 1040.
Patel, C.; Sunoj, R. B.; 'TiCl4 Promoted Baylis-Hillman Reaction: Mechanistic Rationale Toward Product Distribution and Stereoselectivity' J. Org.
Chem. 2010, 75, 359.
Shinisha, C. B.; Sunoj, R. B.; 'The pivotal role of chelation as a stereochemical control element in non-Evan's anti aldol product formation' Org. Lett. 2010, 12, 2868.
Sharma, A. K.; Sunoj, R. B.; 'Enamine versus Oxazolidinone: What Controls Stereoselectivity in Proline-Catalyzed Asymmetric Aldol Reactions?' Angew.
Chemie. Int. Ed. 2010, 49, 6373.
Shinisha, C. B.; Sunoj, R. B.; 'Transition State Models for Probing Stereoinduction in Evans Chiral Auxiliary-Based Asymmetric Aldol Reactions'
J. Am. Chem. Soc. 2010, 132, 12315.
Patil, M. P.; Sharma, A. K.;Sunoj, R. B.; 'On the Importance of the Nature of alpha-Substituents in Pyrrolidine
Organocatalysts in Asymmetric Michael Additions'
J. Org. Chem. 2010, 75, 7310.
Janardanan, D.; Sunoj, R. B.; 'Chemo-, Regio-, and
Diastereoselectivity Preferences in the Reaction of Sulfur Ylide with Dienal and
Enone'
Org. Biomol. Chem. 2011, 9, 1642.
Rajeev, R.; Sunoj, R. B.; 'Mechanism and Electronic Effects in Nitrogen Ylide-Promoted Asymmetric Aziridination Reaction'
Org. Biomol. Chem. 2011, 9, 2123.
Kumari, M.; Balaji, P. V.; Sunoj, R. B.; 'Quantification of Binding Affinities of Essential Sugars with Tryptophan Analogue and the Ubiquitous Role of C-H...pi interactions'
Phys. Chem. Chem. Phys. 2011, 13, 6517.
Sharma, A. K.; Sunoj, R. B.; 'Stereocontrol in
Proline-Catalyzed Asymmetric Amination: A Comparative Assessment of the Role of
Enamine Carboxylic Acid and Enamine Carboxylate'
Chem. Commun. 2011, 47, 5759. Verma, P.; Patni, P.; Sunoj, R. B. ; 'Mechanistic Insights on N-Heterocyclic Carbene Catalyzed Annulations: The Role of Base-Assisted Proton Transfers '
J. Org. Chem. 2011, 76, 5606. Anand, M.; Sunoj, R. B. ; 'Palladium(II)-Catalyzed Direct Alkoxylation of Arenes: Evidence for Solvent Assisted Concerted Metallation Deprotonation'
Org. Lett. 2011, 13 , 4802. |
REVIEWS AND
BOOK CHAPTERS
Shinisha, C. B.; Janardanan, D.; Sunoj, R. B. 'Design of Catalysts for Aymmetric Organic Reactions through Density Functional Calculations' in the book entitled 'Challenges and Advances in Computational Chemistry and Physics' Edited by Jerzy Leszczynski, Springer Science 2010.
Singh, H. B.; Mukherjee, A.; Zade, S.; Sunoj, R. B.; 'Organoselenium Chemistry: Role of Intramolecular Interactions' Chem. Rev. 2010, 110,
4357.
Sunoj, R. B.; 'Proline-Derived Organocatalysis
and Synergism between Theory and Experiments' Wiley Interdisciplinary Reviews (WIRES): Computational Molecular Sciences 2011, (Accepted).
Sunoj, R. B.; 'Theoretical Aspects of Organoselenium Chemistry'
' in Patai's Chemistry of Functional Group, Zvi Rapporport (Editor), Wiley 2011,(in press).
AWARDS AND
DISTINCTIONS
K. R.
Krishna Iyer Memorial Gold medal for outstanding academic achievements for the
year 1996,
Gold
Medallist in M. Sc. (Chemistry), 1996,
Best PhD thesis award, 2001,
Department of Organic Chemistry, Indian
Chemical Research Society of
Associateship
of the Indian
IIT Bombay Young Investigator Award 2006.
National Academy of Sciences India Young Scientist Platinum Jubilee Award 2008.
IIT Bombay 'Excellence in Teaching' Award 2009.
INVITED LECTURES
RESEARCH GROUP (2010)
Computational Chemistry Group (CCG)
RESEARCH SCHOLARS
(CSIR/JRF/SRF)
Rajeev, R. (Stereoselective Transformations) Manju Kumari (Jointly
with Prof. P. V. Balaji, Bioschool: Intermolecular Interactions in Sugar
Chemistry)
Akhilesh Sharma
(Organocatalysis)
Garima Jindal
(Mechanisms of Biosynthetic Pathways)
Hemata K. Kisan
Dilna, S.
Athira, C.
M.Sc.
(Undergraduate) RESEARCHERS
Arkajyoti Sengupta
Yernaidu Reddi
Megha Anand
Srinithya Nair
Ramesh, R
Pritha Verma
Abhishek Parija
Akaksha Thawani (B.Tech. Chem. Engg.)
Santanu Malakar
Alumni
1. Dr. Mahendra P. Patil (Currently at Max-Plank Institute for Kolhenforschug)
2. Dr. Deepa Janardanan (Currently at Hebrew University, Jerusalem)
3. Dr. Dipankar Roy (Currently at City University of New York)
4. Dr. C. B. Shinisha