title: Terminating Catalytic Asymmetric Heck Cyclizations by Stereoselective Intramolecular Capture of η-Allylpalladium Intermediates: Total Synthesis of (-)-Spirotryprostatin B and Three Stereoisomers.
abstract: A catalytic intramolecular Heck reaction, followed by capture of the resulting η(3)-allylpalladium intermediate by a tethered diketopiperazine, is the central step in a concise synthetic route to (-)-spirotryprostatin B and three stereoisomers. This study demonstrates that an acyclic, chiral η(3)-allylpalladium fragment generated in a catalytic asymmetric Heck cyclization can be trapped by even a weakly nucleophilic diketopiperazine more rapidly than it undergoes diastereomeric equilibration.
authors: Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, CA 92697-2025.
authors: Larry E
authors: LE
authors: Overman
authors: Mark D
authors: MD
authors: Rosen