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Congratulations to Sinisa — First Place in the Organic Division - Undergraduate Poster Competition at the 92nd Canadian Chemistry Conference and Exhibition, Hamilton May 30 - June 3, 2009 Chemistry and Biochemistry-current page CCMR (Centre for Catalysis & Materials Research) Courses - 59-230/232 old 59-331/333 531/431 Note: the lab isn't this clean anymore James Green Professor Organic and Organometallic Chemistry
B.Sc. 1982, University of Windsor Ph.D. 1987, University of Waterloo (V.A. Snieckus) NSERC Postdoctoral Fellow, University of California at Berkeley (K.P.C. Vollhardt) NSERC University Research Fellow 1989-99 Office: 358 Essex Hall (Lab: 356 Essex Hall) Phone: (519) 253-4232 ext 3545 or (519) 253-3000 ext 3545 US # (313) 963-6112 ext 3545 e-mail: jgreen at uwindsor.ca Research Interests Our group’s interests are centred on organic synthetic methods which are made possible by the presence of transition metal units complexed to the organic framework on which we wish to carry out reactions. The metal complexation serves to impart new or unusual reactivity which is not normally possible for the organic molecule itself, and to the free the organic portion from the complex. The chemistry is developed to a point where it may be used in natural product and pharmaceutical synthesis. We have three major areas of specific interest currently: 1. We are investigating the synthetic utility of cobalt-alkyne and propargyl cobalt complexes (1). In particular, we are interested in the use of these compounds for the preparation of cycloheptyne-cobalt complexes (2). In contrast to the highly unstable cycloheptane complexes, these complexes are quite stable and can be handled normally. We have been able to make 2 by 4+3 cycloaddition reactions (eqn 1) and by ring closing metathesis (RCM) chemistry. Our interest in 2 stems from their possible use of the ‘hidden’ triple bond in cycloaddition chemistry to give polycyclic frameworks containing seven membered rings, especially the fused 7,5- systems common in so many terpenes. There is also great promise in using allyliron-Fe(CO)4 complexes (3) to make the corresponding cycloheptadiene-iron complexes. There are several related cycloaddition reactions that should be feasible by use of these or closely related propargylcobalt or allyliron cations, and we intend to look at these, too.
2. We are engaged in the study of reactions of bis(propargylcobalt) complexes (4) (actually generated one-at-a-time) and bis(allyliron) complexes, and their application in the synthesis of compounds containing skipped (i.e., non-conjugated) dienes, diynes, and enynes; these latter structural features common in such types of natural products as leukotrienes and petrocortynes. Along the way, we have found that 4 is excellent for giving rapid access to metacyclophanes such as 5, and as a result we are also looking at the cyclophane syntheses made possible by these and related dication equivalents.
3. We are interested in the chemistry of chromium tricarbonyl complexes of aromatic compounds, and particularly in enantiomerically enriched versions of these co mplexes (6). Complexes of this type are excellent at undergoing reactions on the side chains (R1, R2) in a highly stereoselective manner, but there are only a few good methods for the synthesis of these complexes in enantiomerically enriched form. We are developing methods to get access to these compounds based on asymmetric deprotonation reactions of the aromatic ring protons by strong bases. We looking at preparative methods of based on reductive metallation of benzylic acetals and benzylic ethers. Finally, we are exploring the use of the complexes in asymmetric synthesis; for example benzyne complexes such as 7 promise to be very useful reagents in asymmetric cycloaddition reactions. Selected Publications 1. Tjeng, A. A. ; Green, J. R.* “The Synthesis of Velloziolide via Nicholas Reaction Based γ-Carbonyl Cations”, J. Org. Chem., 2009, 74, 7411-7416. 2. Harati, M.; Green, J. R.*; Cooper, b.; Wang, J.* “Gas Production in the Bromate Pyrocatechol Oscillator”, J. Phys. Chem. A., 2009, 113, 6548-6551. 3. Taj, R. A. Green, J. R.* “Cyclohepta[de]naphthalenes and the Rearranged Abietane Framework of Microstegiol via Nicholas Reaction Chemistry”, Synlett, 2009, 292-296. 4. Green, J. R.* “Cycloheptynedicobalt Complexes in Organic Synthesis”, Eur. J. Org. Chem. , 2008, 6053-6062 (invited review)(among top 10 most access EJOC articles, Dec/08) . 5. Amiralaei, S; Green, J. R.* “Generation and reactivity of dehydrotropylium-Co2(CO)6 ion “, Chem. Commun, 2008, 4971-4973. 6. Harati, M.; Amiralaei, S.; Green, J.R*; Wang, J.* “Nonlinear instabilities in the light-mediated bromate - 4-aminophenol reaction”, Photochem. Photobiol. A, 2008, 198, 92-97. 7. Djurdjevic, S.; Green, J. R.* “Dibenzocycloheptynedicobalt complexes via intramolecular Nicholas reactions: the enantioselective synthesis of Allocolchicine NSC 51046”, Org. Lett. , 2007, 9, 5505. (highlighted in SYFACTS, 2008, 330) 8. Li, N.; Green, J. R.*; Wang, J.* “The concurrence of photoreduction and bromination of 1,4-benzoquinone in aqueous solution”, Chem. Phys. Lett., 2007, 447, 241-246. 9. DiMartino, J.; Green, J. R.* “Lewis and Protic Acid Mediated Nicholas Reactions of 3-Acetoxycyclohept-1-en-4-ynedicobalt Hexacarbonyl: Site Selectivity of Nucleophile Incorporation”, Tetrahedron, 2006, 62, 1402. 10. Mohamed, A. B.; Green, J. R.; Masuda, J. “Intramolecular Pauson-Khand reactions of cycloheptynedicobalt complexes”, Synlett, 2005, 1543-1546. 11. Green, J. R. “α -Lithiocarboxyllic Acids and Other Li-C-CXYZ Compounds In " Science of Synthesis (SoS): the Houben-Weyl for the next Millennium" Volume 8a Group 1 (Li, Na, K, Rb, Cs), Majewski, M.; Snieckus, V., L., Eds., Ch. 8.1. 15, Thieme, 2005. 12. Ding, Y.; Green, J. R.* "Benzocycloheptynedicobalt Complexes by Intramolecular Nicholas Reactions", Synlett, 2005, 271-274.. 13. Guo,R.; Gibe, R.; Green, J. R.* “Mono- and Disubstitutions of (Hepta-2,5-diyne-1,7-diol) Bis(dicobalt) Derivatives: Selectivity in Nicholas Reactions”, Can. J. Chem., 2004, 82, 366-374. 14. Mohamed, A. B.; Green, J. R.* , “Tethered 2+2+2 cycloaddition reactions of cobalt cycloheptyne complexes”, Chem. Commun., 2003, 2936-2937. 15. Akhter, S.: Green, J. R.; Thatcher, G. J.; Mutus, B.* (2003) "Peroxynitrite and NO+ donors form coloured nitrite adducts with sinapinic acid: potential applications" Nitric Oxide 8, 214-221. 16. Gibe, R.; Green, J. R.*, Davidson, G. Indolophantetrayne Cobalt Complexes via Nicholas Reactions, Org. Lett., 2003 , 5, 1003-1005. 17. Gibe, R.; Green, J. R.* Synthesis of Cyclophanetetrayne Complexes from Bis(propargyldicobalt) Dication Equivalents Chem. Commun. 2002, 1550-1551. Current Group Members Sheida Amiralaei (MSc Cyprus) Isabelle Kolodziej (BSc McMaster) Mariam Mehdi (BSc Windsor) Rafiq Taj (MSc, Punjab) Sudagar Dhaliwal Jake Henkie Links to those acknowledging my acquaintance Canadian Chemistry, Biochemistry Departments |
