Birgir . Gudmundsson -- PhD 1995

Scientific Career

Thesis Title
I. Solution Behavior of Chelated and Non-Chelated Aryllithium Compounds. II. A Mechanistic Study of the Lithium-Selenium Exchange.
Research Summary Biggie started his graduate research with a foray into ate complex chemistry of 2nd and 3rd row elements S, Se and Br. He showed that even selenium could form ate complexes with a properly designed scaffold. This system also allowed the first test of whether ate complexes were true intermediates in the lithium metalloid exchange. The observable ate complex was not an intermediate in the exchange, i.e., the direct substitution on selenium (kdirect) which bypassed the ate complex was at least 100 faster than the path going through the ate complex (kate).

In connection with the work on the structures of various aryllithium reagents Biggie discovered that many aryllithiums formed substantial amounts of triple ions (Ar-Li-Ar- Li+), and this work started the group's foray into chelated organolithium reagents. Biggie carried out a very detailed multinuclear NMR study of the 15N-labeled Hauser compound 2-lithio N,N-dimethylbenzylamine. He showed that several aspects of earlier work on this compound were incorrect, established that there were three "chelation isomers" (A, B, C below) by preparation of Li-6 and N-15 double labelled compounds, and found that the chelated compound was much more strongly dimerized than PhLi itself. These studies were extended by Wayne Goldenberg and Aaron Sanders.

Papers
  1. "The First Organoselenium Ate Complex," Hans J. Reich, Birgir Ö. Gudmundsson and Robert R. Dykstra, J. Am. Chem. Soc. 1992, 114, 7937. (Communication). PDF

  2. "Solution Structure of 2-[(Di-methyl-amino)-methyl]phenyllithium," Hans J. Reich and Birgir Ö. Gudmundsson, J. Am. Chem. Soc. 1996, 118, 6074-6075. (Communication). PDF

  3. "Triple Ion Formation in Localized Organolithium Reagents," Hans J. Reich, William H. Sikorski, Birgir Ö. Gudmundsson and Robert R. Dykstra, J. Am. Chem. Soc. 1998, 120, 4035. (Communication).PDF

  4. "Aggregation and Reactivity of Phenyllithium Solutions," Hans J. Reich, D. Patrick Green, Marco A. Medina, Wayne S. Goldenberg, Birgir Ö. Gudmundsson, Robert R. Dykstra, and Nancy H. Phillips, J. Am. Chem. Soc. 1998, 120, 4035. (Article). PDF Suppl.

  5. "Amine-Chelated Aryllithium Reagents - Structure and Dynamics." Hans J. Reich, Wayne S. Goldenberg, Birgir Ö. Gudmundsson, Aaron W. Sanders, Klaus J. Kulicke, Katya Simon, and Ilia A. Guzei J. Am. Chem. Soc. 2001, 123, 8087-8079.(Article) PDF Suppl.

  6. "Are Ate Complexes True Intermediates in the Lithium-Metalloid Exchange? Subtle Effects of Ion Pair Structure in Lithium-Tellurium and Lithium-Selenium Exchange Reactions," Hans J. Reich, Martin J. Bevan, Birgir Ö. Gudmundsson and Craig L. Puckett, Angew. Chem. Int. Ed. Engl. 2002, 41, 3436-3439. (Communication) PDF

  7. "The Role of Ate Complexes in the Lithium-Sulfur, Lithium-Selenium and Lithium-Tellurium Exchange Reactions," Hans J. Reich, Birgir Ö. Gudmundsson, D. Patrick Green, Martin J. Bevan, and Ieva L. Reich, Helv. Chim. Acta 2002, 85, 3748-3772. (Article) PDF

Current Position Lecturer BG
Web address: Tandur Company

Biggie and Gully on the Kickapoo River (probably before they tipped...)


For comments, additions and corrections, send e-mail to Hans J. Reich