Toward the stabilization of fused tricyclic-tris(carbenes)

ORGN 389

Anthony J. Arduengo III and Luigi I. Iconaru, icona001@bama.ua.edu. Department of Chemistry, University of Alabama, 250 Hackberry Lane, Shelby Hall, Tuscaloosa, AL 35401
On route to the fused tricyclictris(carbene) (1), hexamethyltricyclicbis(urea) chloroformamidinium chloride (3) was prepared as a moisture sensitive white solid by chlorination of the hexamethyltricyclictris(urea) (2).1,2 The oxidative addition of the hexamethyltricyclicbis(urea) chloroformamidinium chloride (3) to M0(PPh3)4 (M0=Pd, Pt) afforded carbene-metal (II) complexes (4 and 5). Only the cis- isomer is observed for the palladium (II)-carbene complex (with carbene center resonance at δ 199.7) whereas in the case of platinum, both isomers are observed (carbene center resonances for cis- and trans- isomers at δ 184.5 and 182.4, respectively). The configurations of the complexes have been established by NMR spectroscopy (1H-, 13C-, 31P-, HMBC, HSQC, NOESY). Theoretical models also supported the proposed geometry of the carbene-palladium (II) complex. Work is currently in progress for the determination of the catalytic activity of the carbene-palladium (II) complex.


*We gratefully acknowledge support for this research from the National Science Foundation (CHE-0115760), E.I. Du Pont de Nemours and Co., Inc., and Department of Energy, Office of Renewable Energy under the Hydrogen Storage Grand Challenge, Solicitation no. DE-PS36-03GO93013.

1. Arduengo, A. J., III; Li, W. Unpublished results

2. Li, W. Dissertation Thesis 2004


 

Heterocycles and Aromatics, Molecular Recognition and Self Assembly
8:00 PM-10:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Hall A, Poster

Division of Organic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008