73900-18-2Relevant academic research and scientific papers
Iterative reactions of transient boronic acids enable sequential C-C bond formation
Battilocchio, Claudio,Feist, Florian,Hafner, Andreas,Simon, Meike,Tran, Duc N.,Allwood, Daniel M.,Blakemore, David C.,Ley, Steven V.
, p. 360 - 367 (2016/04/04)
The ability to form multiple carbon-carbon bonds in a controlled sequence and thus rapidly build molecular complexity in an iterative fashion is an important goal in modern chemical synthesis. In recent times, transition-metal-catalysed coupling reactions
Intervention of carbonyl and oxonium ylides in reactions of [(alkoxycarbonyl)phenyl]carbenes in the gas phase forming 3-alkylphthalides and 2-alkoxy-1(2H)-benzocyclobutenone. 13C and 18O labeling studies
Tomioka, Hideo,Kobayashi, Noriyuki,Murata, Shigeru,Ohtawa, Yasuki
, p. 8771 - 8778 (2007/10/02)
The generation of isomeric [(methoxycarbonyl)phenyl]carbenes (6a-c) by flash vacuum pyrolysis (FVP, 350-450 C, 10-5 Torr) of the corresponding diazomethanes (1a-c) produced 3-methylphthalide (2) and 2-methoxy-l(2H)-benzocyclobutenone (3), presumably as a result of carbene-carbene rearrangement followed by the interaction of the methoxycarbonyl group with the carbene center in the ortho isomer (6a). Labeling studies were carried out in order to determine the mechanism of the reaction. Thus, FVP of [o-(carboxy-13C](methoxycarbonyl)phenyl]diazomethane produced 3-methyl[carbonyl-13C]phthalide and 2-methoxy-1(2H)-[carbonyl-13C]benzocyclobutenone, thereby indicating that 3 was formed via Stevens-type migration of the acyl group in an oxonium ylide intermediate (9). FVP of [p-[carfronyl-18O](methoxycarbonyl)phenyl]diazomethane, on the other hand, produced 3-methyl[ether-18O]phthalide, along with a small amount of 3-methyl[carbonyl-18O]phthalide and 3-methoxy-1(2W)-[carbonyl-18O]benzocyclobutenone, indicating that 2 was produced mainly via 1,5-methyl migration in a carbonyl ylide intermediate (7). Generation of other [(alkoxycarbonyl)phenyl]diazomethanes (16, where alkoxy = EtO and PriO) under similar conditions also produced 3-alkylphthalides (17) and 2-alkoxybenzocyclobutenones (18), but phthalide 19, which was not detected in the FVP of 1, was also formed in this case, presumably as a result of α,β-elimination of alkenes in the oxonium ylide. These results showing the intervention of the oxonium ylide of the ester group are in marked contrast to the observation that, at much lower temperatures in the liquid and solid phases, only the carbonyl ylide has been involved.
Regioselectivity in the Addition of Singlet and Triplet Carbenes to 1,1-Dimethylallene. A Probe for Carbene Multiplicity
Creary, Xavier
, p. 1611 - 1618 (2007/10/02)
Singlet carbenes add preferentially to the more substituted bond of 1,1-dimethylallene (1), to give methylenecyclopropanes 3 as the major product.In contrast, many triplet carbenes add with differing regioselectivity, giving the thermodynamically preferre
