Buchner reaction

Scheme 13.13 t-Acid ligand-promoted Buchner reaction in metathesis catalysts... 

Buchner reaction (1, 368-369). The reaction of benzene with an alkyl diazoacetate is catalyzed efficiently by rhodium(Il) carboxylates, particularly Rh(OCOCF3)2. Cyclohcptatricnes are formed at room lemperlure. Of more importance, the l-carboalkoxy-2,4,6-cycloheptatriene is formed in almost quantita-... 

Silver scorpionate (41) catalysed the Buchner reaction, yielding the cyclohepta-trienes (43) from the corresponding aromatics (42).42... 

Four optically active cycloheptatriene derivatives carrying a methoxy group(s) at different positions were prepared by the pentane-2,4-diol-tethered Buchner reaction (g) (Scheme 13).24 In addition to the high stereoselectivity, the tether also controlled the regioselectivity. 

Ultimately it was found that by conducting the reaction with benzene in CH2C12 or in neat benzene, the ring expansion product 30a, via the norcaradiene 29a (Buchner reaction), was obtained in good yield (Scheme 8.5).17 Evaluation of the substrate... 

TABLE 8.1. Yields and Isomer Ratios of the Silver-Catalyzed Buchner Reaction of Benzene Derivatives with EDA... 

Intramolecular Buchner reaction. Rh(OAc), is more efficient than CuCl as the catalyst for cyclization of the a-diazo ketone 1, derived from 3-phenylpropionic acid, to bicyclo 5.3.0]decatrienone (2). This product isomerizes in the presence of triethylamine to the more stable trienone 4. A useful isomerization to 3-tetralone (3) occurs in the presence of trifluoroacetic acid. 

The total synthesis of the diterpenoid tropone, harringtonolide was accomplished in the laboratory of L.N. Mander. The key step to form the seven-membered ring was the Buchner reaction of a complex polycyclic diazo ketone intermediate. Upon treatment with rhodium mandelate, an unstable adduct was formed and was immediately treated with DBU to afford the less labile cycloheptatriene. 

Buchner Method of Rinq Enlarqement (Buchner Reaction) 68... 

Buchner Method of Rina Expansion (Buchner Reaction. ... 

Duddeck, H., Ferguson, G., Kaitner, B., Kennedy, M., McKervey, M. A., Maguire, A. R. The intramolecular Buchner reaction of aryl diazoketones. Synthesis and x-ray crystai structures of some poiyfunctionai hydroazuiene iactones. J. Chem. Soc., Perkin Trans. 11990, 1055-1063. 

Cordi, A. A., Lacoste, J. M., Hennig, P. A reinvestigation of the intramoiecuiar Buchner reaction of 1-diazo-4-phenyibutan-2-ones ieading to 2-tetraiones. J. Chem. Soc., Perkin Trans. 1 1993, 3-4. 

Manitto, P., Monti, D., Speranza, G. Rhodium(ii)-Cataiyzed Decomposition of 1-Diazo-4-(2-naphthyi)butan-2-one. Direct Chemicai Evidence for the Formation of the Norcaradiene System in the intramoiecuiar Buchner Reaction. J. Org. Chem. 1995, 60, 484-485. 

Buchner reaction. One example of the Buchner method of ring enlargement, the reaction of ethyl diazoacetate with benzene, was reinvestigated by Grundmaim and... 

Ffau and Plattner employed a Buchner reaction for the synthesis of vetiva-zulene from the Indane derivative I. At the high temperature at which the condensation of I with ethyl dlazoacetute was carried out the adduct 11 was in part isomerized to III suponiilcation of the mixture completed the Isumoij/.iition, and dehydrogena-... 

Cu(TpMs)] catalyzes the addition of the iCHCC Et unit (derived from N2HCHCC>2Et) to benzene which yields a cycloheptatriene ring, in analogy with the Buchner reaction. When alkyl groups are linked to the aromatic rings, the selectivity of the reaction can be oriented toward insertion into an alkyl C-H bond by using [Cu(TpMs)].48 On the other hand, [Cu(Tp )] efficiently catalyzes the insertion of... 

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