The rhodium carbene route to oxazoles: a remarkable catalyst effect.
Dirhodium tetraacetate catalysed reaction of alpha-diazo-beta-keto-carboxylates and -phosphonates with arenecarboxamides gives 2-aryloxazole-4-carboxylates and 4-phosphonates by carbene N-H insertion and cyclodehydration; in stark contrast, dirhodium tetrakis(heptafluorobutyramide) catalysis results in a dramatic change of regioselectivity to give oxazole-5-carboxylates and 5-phosphonates.
Shi
Baolu
B
School of Chemistry, University of Nottingham, University Park, Nottingham, UK NG7 2RD.
Blake
Alexander J
AJ
Campbell
Ian B
IB
Judkins
Brian D
BD
Moody
Christopher J
CJ
D000577:Amides / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D004952:Esters / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D010080:Oxazoles / Q000138:chemical synthesis*; D012238:Rhodium / Q000737:chemistry*
D000577:Amides; D004952:Esters; D010080:Oxazoles; C030011:carbene; D012238:Rhodium; D008697:Methane