104620-37-3

Upstream product

• 104620-36-2 methyl 2-diazo-3-oxo-4-phenylheptanoate 

Relevant academic research and scientific papers

Dirhodium(II) tetrakis(perfluoroalkylbenzoates) as partially recyclable catalysts for carbene transfer reactions with diazoacetates

Three highly fluorinated dirhodium(II) tetrakis(benzoates), [Rh2(O2CRF)4, RF=C6H4-4-C6F13 (3) and C6H3-3,5-di(CnF2n+1) (n=6: 4; n=8: 5)], have been prepared and characterized. Only 4 and 5 are suited for applications in fluorous synthesis due to their excellent solubility in fluorous solvents. They were found to catalyze the following carbenoid reactions of diazo compounds in the fluorous solvents 1,1,2-trichloro-1,2,2-trifluoroethane and perfluoro(methylcyclohexane): cyclopropanation of styrenes using methyl diazoacetate, intermolecular carbene C-H insertion into hexane with methyl diazoacetate, and intramolecular aromatic C-H insertion of an α-diazo-β-ketoester. Except for the second reaction type, the catalyst could be recovered to a high extent by a liquid-liquid extraction (fluorous solvent - dichloromethane) due to its preference for the fluorous solvent. For the cyclopropanation reactions, the recovered catalyst was used in four subsequent reaction/workup cycles without significant loss of activity. In contrast, the catalyst could not be recovered from the carbenoid C-H insertion reaction with hexane; apparently, some by-products of this sluggish reaction, such as carbene dimers and oligomers, caused the deactivation or destruction of the catalyst.

Calixarenes as ligands for transition-metal catalysts: A bis(calix[4]arene-11,23-dicarboxylato) dirhodium complex

A novel dirhodium tetracarboxylate complex is described in which two calix[4]arene macrocycles, bridged at the upper rim by a Rh-Rh unit, serve as ligands and whose solid-state structure shows an unusual coordination of a toluene molecule in the axial pos

New highly fluorinated dirhodium(II) tetrakis(alkanecarboxylates) as catalysts for carbenoid C-H insertion reactions

Six highly fluorinated dirhodium(II) tetrakis(alkanecarboxylates) [Rh2(OOCRF)4, RF = C7F15, CH2C6F13, CH2CH2C6F13, CH2CH2C8F17, CH2CH2C10F21, and CH2OCH2CH2C10F21] were prepared and characterized. Their suitability as catalysts for intermolecular carbenoid C-H insertion was investigated for the reaction of methyl diazoacetate with hexane. In the frame of fluorous synthesis, only Rh2(OOCC7F15)4 and Rh2(OOCCH2C6F13)4 are interesting, since they are soluble in perfluoro(methylcyclohexane) and catalyze the C-H insertion reaction more effectively than all other catalysts, including Rh2(OAc)4. The same two catalysts were also used to achieve 1,5-cyclization of an α-diazo-β-keto ester by intramolecular C-H insertion. Unfortunately, deterioration of the catalysts occurs to a significant extent during all reactions, and therefore, the possibilities to recover and reuse them are rather limited.

Highly Selective Insertion into Aromatic C-H Bonds in Rhodium(II) Triphenylacetate-catalysed Decomposition of α-Diazocarbonyl Compounds

Rhodium(II) triphenylacetate, which features a bulky bridging ligand, has been demonstrated to exhibit an exceptionally high order of selectivity for aromatic C-H insertion over aliphatic C-H insertion or cyclopropanation in catalytic decompositions of α-