Solid-phase rhodium carbenoid reactions: an N-H insertion route to a diverse series of oxazoles.
[reaction: see text] The solid-phase synthesis of a series of oxazoles is described. The key step in the construction of these molecules involves the rhodium-catalyzed decomposition of polymer-bound alpha-diazo-beta-ketoesters. These reactions are performed in the presence of primary amides and yield the corresponding N-H insertion products. Subsequent cyclodehydration of these alpha-(acylamino)-beta-ketoesters provides the corresponding resin-bound 2,5-disubstituted oxazoles, which are further elaborated during cleavage from the resin.
Clapham
B
B
Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Spanka
C
C
Janda
K D
KD
D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D003500:Cyclization; D008956:Models, Chemical; D015394:Molecular Structure; D010080:Oxazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D000588:Amines; D010080:Oxazoles; D012238:Rhodium