On the synthesis of Z-gamma-amino-alpha,beta-unsaturated esters via Ru-catalyzed coupling.
[formula: see text] A synthesis of gamma-amino acids and their cyclic derivatives, 3-pyrrolinones, from alpha-amino acids employs a ruthenium-catalyzed Alder ene reaction as a key step in the sequence. Cyclopentadienylruthenium (1,4-cyclooctadiene) chloride catalyzes the addition of gamma-amido-alpha,beta-alkynoate esters with monosubstituted alkenes. The major product arises from C-C bond formation at the alpha-carbon of the alkynoate. The reaction exhibits high chemoselectivity. The ruthenium-catalyzed addition occurs in preference to a Diels-Alder reaction. The two new double bonds are created with complete geometrical control. The initial gamma-amido-alpha,beta-unsaturated ester can be cyclized to the pyrrolinones with a tin catalyst.
Trost
B M
BM
Department of Chemistry, Stanford University, California 94305-5080, USA. bmtrost@leland.stanford.edu
Roth
G J
GJ
D000475:Alkenes / Q000138:chemical synthesis / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry; D000577:Amides / Q000138:chemical synthesis*; D002384:Catalysis; D003500:Cyclization; D004952:Esters / Q000138:chemical synthesis*; D010084:Oxidation-Reduction; D012428:Ruthenium / Q000737:chemistry*; D014001:Tin
D000475:Alkenes; D000480:Alkynes; D000577:Amides; D004952:Esters; D014001:Tin; D012428:Ruthenium