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Roderick BATES
bates

Associate Professor

Associate Chair (Faculty)

Education: B.Sc., Ph.D., London Imperial College, Post-doc: Colorado State University

Research Area: Organic Chemistry

Phone: (65) 6316 8907

E-mail: roderick@ntu.edu.sg

Webpage: http://www1.spms.ntu.edu.sg/~roderick/



Research Interest

Allene Chemistry and Alkaloid Synthesis

I am interested in the development of synthetic methodology and in the total synthesis of natural products. For some time we have been exploring allene cyclisation reactions, in which intramolecular nucleophilic attack is triggered by a metal reagent – originally acyl cobalt complexes, but now employing the Claesson rearrangement using silver and gold. A recent theme has been the use of hydroxylamines as tethered nitrogen nucleophiles. This led to the synthesis of sedamine. A combination of this hydroxylamine chemistry and some recently developed iminium ion chemistry has resulted in syntheses of porantheridine, sedinine and several of the Nuphar alkaloids. Gold(III) catalysis of a highly stereoselective allene cyclisation has also been used in a formal synthesis of swainsonine.

 

Intramolecular Propargylic Barbier Reaction


Our interest in allene chemistry has also led us to a highly stereoselective syntheses of (-)-mintlactone and stemoamide using the intramolecular variant of the propargylic Barbier reaction.


Metathesis - Michael

We have shown that a sequence of cross-metathesis and intramolecular conjugate addition is an efficient method to make tetrahydro-[1,2]-oxazines, useful intermediates for alkaloid synthesis. We have used this method to synthesise an indolizidine alkaloid, monomorine I. The strategy has being extended to the synthesis of 2,6-cis-tetrahydropyrans, such as Diospongin A and the THP core of Clavosolide A. Under kinetic conditions, the less stable 2,6-trans isomers can be formed. We have used this to the THP moiety of bistramide D.

 

Natural Product Synthesis

The briaranes are a large family of natural products. We are engaged in developing synthetic methods for this class of compounds using the Diels-Alder reaction and an eclectic range of other reactions.


Selected Publications

  1. Model Studies Towards the Bistramide D Tetrahydropyran, R. W. Bates K. Palani, Tetrahedron Lett., 2008, 49, 2832.

  2. A Synthesis of (±)-Stemoamide using the Intramolecular Propargylic Barbier Reaction, R. W. Bates, S. Sridhar, Synlett, 2009, 1979.

  3. A Formal Synthesis of Swainsonine by Gold Catalysed Allene Cyclisation, R. W. Bates, M. R. Dewey, Org. Lett., 2009, 11, 3706.

  4. Synthesis of the Northern Hemisphere of the Briaranes, R. W. Bates, A. Pinsa, X. Kan, Tetrahedron, 2010, 66, 6340.

  5. A Synthesis of (-)-Sedinine by Allene Cyclisation and Iminium Ion Chemistry, R. W. Bates, Y. Lu, Org. Lett., 2010, 12, 3938.