104037-26-5Relevant articles and documents
Observations concerning the synthesis of heteroatom-containing 9-membered benzo-fused rings by ring-closing metathesis
Aderibigbe, Blessing A.,Green, Ivan R.,Mabank, Tanya,Janse van Rensburg, Mari,Morgans, Garreth L.,Fernandes, Manuel A.,Michael, Joseph P.,van Otterlo, Willem A.L.
, p. 4671 - 4683 (2017)
A set of benzo-fused dienes with a 1,9-relationship and containing a variety of nitrogen and oxygen heteroatoms was readily synthesized. These dienes were then treated with the Grubbs second generation catalyst with the aim of synthesizing the 9-membered benzannelated heterocycles containing two heteroatoms (either O,O, NR,NR or O,NR where R = Ts or Boc). As previously observed in the literature, many of the dienes did not give the expected ring-closed product. However, a number of the desired products did form, namely with the 1,2-dihydrobenzo[c][1,5]oxazonin-7(5H)-one, 5,7-dihydrobenzo[b][1,5]oxazonine-6(2H)-carboxylate and 2,5,6,7-tetrahydrobenzo[b][1,5]oxazonine cores, albeit in poor yields. Rather surprisingly, the N-allyl-N-(2-(N-allyl-4-methylphenylsulfonamido)benzyl)-4-methylbenzenesulfonamide scaffold gave the desired ring-closed 1,6-ditosyl-2,5,6,7-tetrahydro-1H-benzo[b][1,5]diazonine in a high yield. Furthermore, when treated with the catalyst [RuClH(CO)(PPh3)3] the alkene isomerized into conjugation only with the benzylic NTs group and not with the phenyl NTs group to afford the 1,6-ditosyl-2,3,6,7-tetrahydro-1H-benzo[b][1,5]diazonine structure.
Intramolecular reactions of metal carbenoids with allylic ethers: Is a free ylide involved in every case?
Clark, J. Stephen,Hansen, K. Emelie
supporting information, p. 5454 - 5459 (2014/05/20)
Rhodium-, copper- and iridium-catalyzed reactions of the 13C-labelled diazo carbonyl substrates 18* and 19* were performed. Results obtained from copper- and iridium-catalyzed reactions of the 13C-labelled α-diazo β-keto ester 19* indicate that either or both of these reactions do not proceed via a free oxonium ylide but instead follow a competing non-ylide route that delivers apparent [2,3]-sigmatropic rearrangement products. In the case of the iridium-catalyzed reaction of α-diazo β-keto ester 19*, results obtained from crossover experiments indicate that the initially formed metal-bound ylide dissociates to give an iridium enolate and an allyl cation, which recombine to form the C-C bond. Differing distributions of 13C-labelled rearrangement products in the rhodium-, copper- and iridium-catalyzed reactions of a 13C-labelled α-diazo β-keto ester (see scheme, DCE=dichloroethane, acac=acetylacetonate, COD=1,5-cyclooctadiene) revealed that the copper- and iridium-mediated reactions do not proceed via a common free oxonium ylide intermediate.
1,3-Dipolar Cycloadditions of Nitrones Derived from the Reaction of Acetylenes with Hydroxylamines
Padwa, Albert,Wong, George S. K.
, p. 3125 - 3133 (2007/10/02)
A study of the reaction of hydroxylamines with a variety of acetylenes has been carried out.Methylhydroxylamine readily reacts with methyl propiolate to give methyl 4-carbomethoxy-2-methyl-4-isoxazolidine-3-acetate.Further heating of this material results
