Step economy and the ideal synthesis: The design of new transition metal-catalyzed reactions

ORGN 894

Mitchell P. Croatt, mcroatt@stanford.edu1, Paul A. Wender, wenderp@leland.stanford.edu2, and Nicole M. Deschamps, nicolemd@stanford.edu1. (1) Department of Chemistry, Stanford University, Rothway, Stanford, CA 94305, (2) Department of Chemistry and Department of Molecular Pharmacology, Stanford University, Stanford, CA 94305
In order to achieve more step-economical syntheses our organometallic subgroup has focused on the invention or discovery of new reactions with a special emphasis on processes that greatly increase molecular complexity and are forbidden or difficult to achieve in the absence of a catalyst. Recently, new multicomponent reactions have been designed via trapping of the organometallic intermediates with additional components. For example, intermediates from our original metal-catalyzed [4+2] cycloaddition have been trapped with carbon monoxide (CO) to produce the [4+2+1] and dienyl-Pauson-Khand reactions. The observed rate enhancement with the dienyl-Pauson-Khand reaction was used in the design of a diene-ene [2+2+1] reaction, the first metal-catalyzed [2+2+1] reaction of two olefins and CO (eq 1). A subsequent study of the diene-allene [2+2+1] reaction resulted in a high-yielding method for the construction of highly substituted cyclopentanones (eq 2). The design, development, and scope of the diene-ene and diene-allene [2+2+1] reactions will be discussed.

 

New Reactions and Methodology
8:00 AM-11:40 AM, Thursday, 14 September 2006 Moscone Center -- Room 133, Oral

Division of Organic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006