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Department
of Chemistry, Kings
College, Strand London,
WC2 R2LS, UK. |
e-mail
:vmswamy@yahoo.com vmswamy@hotmail.com |
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Ph.D.
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August 2000, National Chemical Laboratory |
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Thesis title |
Stereoselective
Functionalisation and C-C Bond Formation on Transition Metal Template. Supervisor: Dr.
Amitabha Sarkar |
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M.Sc.
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Organic Chemistry, University of Pune, Pune, India, 1995. |
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B.Sc. |
Chemistry (major) with Zoology, Botany and Geology, Nowrosjee
Wadia College, Pune, India, 1993 |
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Senior
Research Fellowship (1998-2001) and Junior Research Fellowship (1996-1998) awarded by Council of
Scientific and Industrial Research,
India on the basis of a nationally competitive examination (NET) |
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Qualified in nationally
competitive GATE-95 with a score of 96.5 percentile |
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NCL-University
Merit Scholarship (1993-1995) |
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* |
Three and a half years
of graduate research on organic/organometallic chemistry. |
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* |
Synthesized alkyllithium /alkylmagnesium reagents,
silyl enol ethers and new arene
chromium complexes. |
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* |
Studied the role of
Lewis acids in stereoselective addition of alkyllithium and alkylmagnesium
reagents to enones anchored by a chromium tricarbonyl group. |
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* |
Synthesized scandium
and rare earth triflate salts as catalysts for highly diastereoselective
Mukaiyama aldol reaction on h6
ortho substituted benzaldehyde chromium complexes
(as well as their dimethyl acetals) at ambient temperature. |
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* |
Devised a convenient
protocol for the addition of silyl enol ethers to enones promoted by bases
like KH, 50% aq. NaOH, and tBuOK.
The protocol is useful for the construction of fused rings if followed by a
Robinson annulation. |
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* |
Experienced in scanning
1D and 2D spectra on Bruker AC-200 and MSL-300 instruments at room
temperature and lower temperatures. |
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* |
Experience in handling
air-sensitive reagents/reactions, isolation and structure elucidation of
organic/ organometallic compounds by IR & NMR (including 2D and DNMR)
spectroscopy. |
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* |
Conversant with modern
separation techniques (GC, and HPLC). |
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* |
Familiar with computer
operating systems DOS and Windows: used MS-OFFICE97, ORIGIN, CHEMWINDOW3.1,
WINNMR, XWINNMR, HYPERCHEM5. |
The objective of the study was to explore various regio- and
diastereoselective C-C bond forming reactions on arene tricarbonylchromium
template. Specifically, the unusual conjugate addition of Grignard reagents to
the enones, and, rare earth triflate catalyzed Mukaiyama aldol reaction on
complexed aldehydes an their dimethyl acetals were studied. Inspired by the
base-induced desilyation of complexed aromatic substrates, desilylation of
silyl enol ethers and their addition to enones under mild conditions was
studied.
Conformationally flexible h6
orthosubstituted benzaldehyde complexes were subjected to Mukaiyama aldol
reaction catalyzed by Scandium and rare earth triflates to obtain the
corresponding aldols with high diastereoselectivity. The corresponding dimethyl
acetals provide similar products with high diastereoseletivity. The steroechemistry
of the new stereogenic center was conformed by crystal structure of
representative complexes as well as CD spectral correlation of optically pure
products.
Conformationally rigid 2-arylidene-1-tetralone-Cr(CO)3
complexes yielded 1,4-adducts by endo-selective
addition of Grignard reagents – explained in terms of magnesium(2+)
coordination to the ketone carbonyl from the exo face in an out-of-plane manner.
The facile desilylation of arylsilanes complexed to Cr(CO)3
group and their additiond to electon deficient led to the study of the cleavage
of silyl enol ethers and their subsequent additions to electrophiles under
basic conditions. Of specific interest was the addition of the silyl enolethers
to enones using common nucleophilic bases like 50% aq. NaOH, KH, and tBuOK leading to the formation of 1, 5
diketones, as a convenient alternative to Mukaiyama-Michael addition.
The Ortho-substituted Arene chromium
complexes provide a planar symmetry since there is no element of symmetry in
these molecules. Unconjugated dienes in these complexes were
diastereoselectively synthesized with complete selectivity. These diene
complexes were then subjected to Ring closing metathesis using the Grubbs
catalyst. It was observed that these complexes underwent facile RCM at a faster
rate compared to the uncomplexed substrates to give cyclic and spirocyclic
ethers, amines and carbocyclic compounds.
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Dr. Amitabha Sarkar Division of Organic Chemistry (Synthesis) National Chemical Laboratory Pune - 411008, India. |
Dr. Ganesh Pandey Division of Organic Chemistry (Synthesis) National Chemical Laboratory Pune
- 411008, India. |
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Prof. M. S. Wadia Emeritus Professor and Former Head, Department of Chemistry, University of Pune, Pune-411 007, India. |
Prof. S. Chandrasekaran Organic Chemistry Indian Institute of Science Bangalore-580012,
India |
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Date of Birth: Jan 28, 1973 |
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Sex: Male |
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Nationality: Indian |
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1. |
Selective deprotection of propargyl ethers using
tetrathiomolybdate. Vishwanath. M. Swamy, Palanichamy Ilankumaran and Srinivasan
Chandrasekaran* Synlett,
1997, (5), 513-514. |
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2. |
Alkali metal hydride or aqueous hydroxide induced conjugate
addition of trimethyl silyl enol ethers to enones. A convenient alternative
to Lewis acid mediated reaction. Vishwanath M. Swamy
and Amitabha Sarkar* Tetrahedron Lett.
1998, 39, 1261-1264 |
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3. |
MgBr2-Directed endo-Selective
Conjugate Addition of Organometallic Reagents to Enones Anchored on Cr(CO)3 Vishwanath M. Swamy
Sunil K Mandal and Amitabha Sarkar* Tetrahedron Lett.
1999, 40, 6061-6064 |
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4. |
Excellent Diastereoselectivity in Triflate-Catalyzed Addition
of Acyclic Enolsilanes to h6-(ortho-substituted-Benzaldehyde)-Cr(CO)3
Complexes Vishwanath M. Swamy,
Mohan M. Bhadbhade, Vedavati G. Puranik and Amitabha Sarkar* Tetrahedron Lett
2000, 41, 6137-6141 |
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5. |
Contra-intutive stereocontrol: endo-selective nucleophilic additions
on an arene-tricarbonylchromium template Amitabha Sarkar, Sambasivam Ganesh, Surojit Sur, Sunil Mandal,
Vishwanath M. Swamy, Bikas Maity. Tipparaju Suresh Kumar J. Organomet. Chem.
2001 (in press) |
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6. |
Stereoselective Synthesis of Cyclic and Spirocyclic Products
by RCM on Arene-chromium Template Bikas Maity, Vishwanath
M. Swamy and Amitabha Sarkar* Tetrahedron Letters
2001 in press |
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1. |
Cleavage of Si-C / Si-O Bond and Thereafter : Alternatives To
Fluorides and Lewis acids. Presented at the National Symposium On the Frontier areas in
Organic Chemistry, Pune, Feb. 1997 |
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2. |
High Diastereoselectivity in C-C Bond Forming Reactions on
Arene-Chromiun Template : Remote Stereocontrol as a Strategy Presented at the National Symposium in Chemistry, Indian
Institute of Science, Bangalore, Jan. 1999 |