Application of peptidyl radicals into a new radical cascade leading to unsaturated gamma-lactams.
Radical cyclization of dipeptides 1a-h proceeds smoothly to give five- and seven-membered rings in good to moderate total yields using Stork's catalytic tin hydride method. A radical is generated on a protecting group and translocated to the peptide moiety. Following a cyclization reaction, the vinyl radical can abstract hydrogen from a benzyl group on an amine, which results in elimination of the protected amine group. Encouraging results have notably been obtained with amino acids other than glycine.
Andrukiewicz
Robert
R
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
Loska
Rafał
R
Prisyahnyuk
Vladimir
V
Staliński
Krzysztof
K
D000596:Amino Acids / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D004151:Dipeptides / Q000737:chemistry*; D007769:Lactams / Q000138:chemical synthesis*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D000596:Amino Acids; D004151:Dipeptides; D007769:Lactams