80-48-8Relevant articles and documents
Ring contraction of N-acetyl-2-aryl-1,2,3,4-tetrahydro-4-quinolones with [hydroxy(tosyloxy)iodo]benzene to trans methyl N-acetyl-2-aryl-2,3-dihydroindol- 3-carboxylates
Kumar, Ashok,Kumar, Sunil,Gupta, Rakesh K.,Kumar, Devinder
, p. 680 - 682 (2007)
The ring contraction of N-acetyl-2-aryl-1,2,3,4-tetrahydro-4-quinolones with [hydroxy(tosyloxy)iodo]benzene to trans methyl N-acetyl-2-aryl-2,3- dihydroindol-3-carboxylates in trimethylorthoformate in good yield is described.
Grob-type fragmentation of 5-oxabicyclo[2.1.1]hexane system: A strategy for synthesis of annulated and 2,2,5-trisubstituted tetrahydrofurans
Mahadevegowda, Surendra H.,Khan, Faiz Ahmed
, p. 8494 - 8504 (2013)
Acid mediated, efficient Grob-type fragmentation reaction facilitated by vicinal ketal and ester moieties in variety of 5-oxabicyclo[2.1.1]hexanes leading to the corresponding annulated and 2,2,5-trisubstituted tetrahydrofurans is reported. Among the Br?nsted and Lewis acids tested, BF 3·OEt2 appears to give the best results, furnishing near quantitative yield (>99%) of tetrahydrofuran tricarboxylate derivatives under mild reaction condition. In case of unsymmetrical monosubstituted 5-oxabicyclo[2.1.1]hexanes two regioisomeric products are obtained. A strategy to transform one of the ester groups of the title compounds to protected hydroxymethyl moiety was evolved, which allows access to differentially protected 2-hydroxymethyl THF derivatives upon fragmentation. Employing TiCl4/R or S-BINOL as chiral Lewis acid, an enantioselective fragmentation (up to 66% ee) was described for the meso bis-furan derivative.
A Scalable Metal-, Azide-, and Halogen-Free Method for the Preparation of Triazoles
Clark, Peter R.,Hayes, Jerome F.,Tomkinson, Nicholas C. O.,Williams, Glynn D.
, p. 6740 - 6744 (2020/03/23)
A scalable metal-, azide-, and halogen-free method for the synthesis of substituted 1,2,3-triazoles has been developed. The reaction proceeds through a 3-component coupling of α-ketoacetals, tosyl hydrazide, and a primary amine. The reaction shows outstanding functional-group tolerance with respect to both the α-ketoacetal and amine coupling partners, providing access to 4-, 1,4-, 1,5-, and 1,4,5-substituted triazoles in excellent yield. This robust method results in densely functionalised 1,2,3-triazoles that remain challenging to prepare by azide–alkyne cycloaddition (AAC, CuAAC, RuAAC) methods and can be scaled in either batch or flow reactors. Methods for the chemoselective reaction of either aliphatic amines or anilines are also described, revealing some of the potential of this novel and highly versatile transformation.
6MNEP: A molecular cation with large hyperpolarizability and promise for nonlinear optical applications
Bloxham, Joseph C.,Brock, Daniel J.,Jackson, Erika W.,Johnson, Jeremy A.,Kenney, Karissa C.,Michaelis, David J.,Smith, Stacey J.,Valdivia-Berroeta, Gabriel A.,Wayment, Adam X.
supporting information, p. 11079 - 11087 (2020/09/09)
Molecular organic crystals are strategically designed for nonlinear optical applications using push-pull chromophores as the core feature. In this approach, electron-donating and accepting groups are connected through a π-conjugated bridge to obtain planar molecules with high hyperpolarizability. However, the non-centrosymmetric packing that is required for nonlinear optical (NLO) applications is a critical challenge that must be addressed to design useful materials. In this article, we present the new organic cation 6MNEP that shows a large hyperpolarizability and can be crystallized in ideal non-centrosymmetric structures for NLO applications, when paired with T and 4NBS anions. The 6MNEP cation was obtained by extending the conjugation length of already existing chromophores. We compare the 6MNEP crystals with other crystals that also have cations with extended conjugation lengths, but result in centrosymmetric crystal structures. Using the effective hyperpolarizability, we found 6MNEP-T and 6MNEP-4NBS to have 1.6 to 2.5 times larger macroscopic nonlinearities than benchmark NLO organic crystals. Additionally, the significantly lower absorption wavelength compared with other state-of-the-art crystals make 6MNEP-T and 6MNEP-4NBS promising materials for NLO applications like intense terahertz generation.