Alkylation of benzene with α-diazoketones via cycloheptatrienyl intermediates
作者:M. Anthony McKervey、D. Noel Russell、M. Fiona Twohig
DOI:10.1039/c39850000491
日期:——
Benzyl ketones can be synthesised efficiently from benzene and α-diazoketones with sequential catalysis by rhodium(II) trifluoroacetate and trifluoroacetic acids; the process involves cycloheptatrienylintermediates.
Rhodium(<scp>ii</scp>)-mediated reactions of thiobenzoylketene S,N-acetals with α-diazo carbonyl compounds: synthesis of 2-substituted 3-alkylamino-5-phenylthiophenes
作者:Hyun Min Song、Kyongtae Kim
DOI:10.1039/b203931a
日期:——
Treatment of 3-methylamino-3-methylsulfanyl-1-phenylpropenethione 1 with excess (2.5 equiv.)
α-diazo carbonyl compounds such as α-diazoketones and α-diazoesters in the presence of a catalytic amount of Rh(II) acetate in CH2Cl2 at rt gave 2-acyl- or 2-aroyl-3-methylamino-5-phenylthiophenes and alkyl 3-methylamino-5-phenylthiophene-2-carboxylates, respectively, as major products along with 1-phenyl-2-methylsulfanylethanones. The formation of the major products indicates that the carbenes or carbenoids generated interact initially with the thione sulfur of 1.
alpha-Diazoketones undergo smooth coupling with thiourea in the presence of 10 mol % of copper(II) triflate to produce the corresponding 2-aminothiazoles in excellent yields with high selectivity. The use of copper(II) triflate makes this method simple, convenient and practical. This method works well with both aryl and alkyl diazoketones to furnish a wide range of 2-aminothiazoles. (C) 2008 Elsevier Ltd. All rights reserved.
Cu(OTf)2-catalyzed synthesis of imidazo[1,2-a]pyridines from α-diazoketones and 2-aminopyridines
-alpha-Diazoketones undergo smooth coupling with 2-aminopyridines in the presence of 10 mol % of copper(II) triflate to produce the corresponding 2-substituted imidazo[1,2-a]pyridines (IPs) in excellent yields with high selectivity. Rh-2(OAc)(4) is also found to be an equally effective catalyst for this transformation. (C) 2007 Elsevier Ltd. All rights reserved.
MCKERVEY, M. A.;RUSSELL, D. N.;TWOHIG, M. FIONA, J. CHEM. SOC. CHEM. COMMUN., 1985, N 8, 491-492
作者:MCKERVEY, M. A.、RUSSELL, D. N.、TWOHIG, M. FIONA