60249-97-0Relevant academic research and scientific papers
Photolabile 2-(2-Nitrophenyl)-propyloxycarbonyl (NPPOC) for Stereoselective Glycosylation and Its Application in Consecutive Assembly of Oligosaccharides
Wang, Jincai,Feng, Yingle,Sun, Taotao,Zhang, Qi,Chai, Yonghai
, p. 3402 - 3421 (2022/03/02)
A photolabile protecting group (PPG) 2-(2-nitrophenyl)-propyloxycarbonyl (NPPOC) was explored in glycosylation and applied in the consecutive synthesis of oligosaccharides. NPPOC displays a strong neighboring group participation (NGP) effect to facilitate the construction of 1,2-trans glycosides in excellent yield. Notably, NPPOC could be efficiently removed by photolysis, and the deprotection conditions are friendly to typical protecting groups. A branched and asymmetric oligomannose Man6 was rapidly prepared, and the consecutive assembly of oligosaccharides without intermediate purification was further investigated owing to the compatibility conditions between NPPPOC's photolysis and glycosylation.
Concise Synthesis of Furo[2,3- b ]indolines via [3,3]-Sigmatropic Rearrangement of N -Alkenyloxyindoles
Shevlin, Michael,Strotman, Neil A.,Anderson, Laura L.
supporting information, p. 197 - 201 (2020/09/21)
A concise new synthetic route to furo[2,3- b ]indolines has been developed by taking advantage of the reactivity of N -alkenyloxyindole intermediates. These compounds spontaneously undergo [3,3]-sigmatropic rearrangement followed by cyclization to form hemiaminals as single diastereomers. Tin-promoted N -hydroxyindole formation followed by conjugate addition to activated alkynes provides simple and modular access to a diverse array of N -alkenyloxyindoles and their corresponding furo[2,3- b ]indolines. Microscale high-throughput experimentation was used to facilitate investigation of the scope and tolerance of this transformation and related studies on the nucleophilic aromatic substitution and rearrangement of N -hydroxyindoles with halogenated arenes have also been evaluated.
Aqueous Titanium Trichloride Promoted Reductive Cyclization of o-Nitrostyrenes to Indoles: Development and Application to the Synthesis of Rizatriptan and Aspidospermidine
Tong, Shuo,Xu, Zhengren,Mamboury, Mathias,Wang, Qian,Zhu, Jieping
supporting information, p. 11809 - 11812 (2015/10/05)
Treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)-H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β-disubstituted o-nitrostyrenes, 2,3-disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure, ready accessibility of the starting materials and good to excellent yields characterize the present transformation. The methodology was used as a key step in a concise synthesis of rizatriptan and a formal total synthesis of aspidospermidine. Mild and efficient treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)-Hamination process. A concise synthesis of a marketed drug (rizatriptan) and a formal total synthesis of aspidospermidine featuring this novel N-heterocyclization process are reported.
Palladium-Catalyzed Formation of N-Heteroarenes from Nitroarenes using Molybdenum Hexacarbonyl as the Source of Carbon Monoxide
Zhou, Fei,Wang, Duo-Sheng,Driver, Tom G.
supporting information, p. 3463 - 3468 (2016/01/25)
The development of a method that employs a two-chamber reaction vessel and uses molybdenum hexacarbonyl [Mo(CO)6] as the carbon monoxide (CO) source for the palladium-catalyzed transformation of nitroarenes into indoles or imidazoles is reported.
NOVEL DENTAL COMPOSITES SYSTEMS AND METHODS OF MAKING THE SAME AND USING SAME
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Paragraph 0033; 0164; 0165, (2015/09/28)
The invention includes a composition comprising a vinyl sulfone monomer, a thiol monomer, and optionally an isocyanate monomer. The invention further includes a composition comprising a composition comprising the tetra(2-mercapto)silane (SiTSH) monomer an
Vinylic MIDA boronates: New building blocks for the synthesis of aza-heterocycles
Llona-Minguez, Sabin,Desroses, Matthieu,Ghassemian, Artin,Jacques, Sylvain A.,Eriksson, Lars,Isacksson, Rebecka,Koolmeister, Tobias,Stenmark, P?l,Scobie, Martin,Helleday, Thomas
supporting information, p. 7394 - 7398 (2015/05/13)
Abstract A two-step synthesis of structurally diverse pyrrole-containing bicyclic systems is reported. ortho-Nitro-haloarenes coupled with vinylic N-methyliminodiacetic acid (MIDA) boronates generate ortho-vinyl-nitroarenes, which undergo a "metal-free" nitrene insertion, resulting in a new pyrrole ring. This novel synthetic approach has a wide substrate tolerance and it is applicable in the preparation of more complex "drug-like" molecules. Interestingly, an ortho-nitro-allylarene derivative furnished a cyclic β-aminophosphonate motif. Old dog, new tricks: A two-step synthesis of structurally diverse pyrrole-containing bicyclic systems is reported. ortho-Nitro-haloarenes coupled with vinylic N-methyliminodiacetic acid (MIDA) boronates generate ortho-vinyl-nitroarenes, which undergo a "metal-free" nitrene insertion, resulting in a new pyrrole ring. This approach has a wide substrate tolerance and it is applicable in the preparation of more complex "drug-like" molecules. Interestingly, an ortho-nitro-allylarene derivative furnished a cyclic β-aminophosphonate motif.
Lipase-mediated resolution of substituted 2-aryl-propanols: Application to the enantioselective synthesis of phenolic sesquiterpenes
Serra, Stefano
experimental part, p. 619 - 628 (2011/07/08)
A comprehensive study of the lipase-mediated resolution of substituted 2-aryl-propanols is reported. The latter alcohols were submitted to the irreversible acetylation catalyzed either by PPL, CRL, or lipase PS. The enantioselectivity of these transformations was dependent on the type of lipase used. The type of substituents and particularly their position on the aromatic ring strongly affected the selectivity of the reaction. The experiments described prove that PPL is the more versatile lipase catalyzing the acetylation with an enantiomeric ratio (E) value that ranges from 1 up to 144, depending on the substrate used. Conversely, the same transformations were catalyzed by CRL and lipase PS with an enantiomeric ratio value, which is always less than 5. The remarkable behavior of PPL was exploited in the large scale resolution of some substituted 2-aryl-propanols whose enantiomeric forms are relevant building blocks in the enantioselective synthesis of phenolic sesquiterpenes. By these means, the synthesis of (S)-turmeronol B and the formal syntheses of (R)-curcumene, (R)-curcuphenol, (R)-xanthorrhizol, and (R)-curcuhydroquinone were accomplished.
Ionic diamine rhodium complex catalyzed reductive N-heterocyclization of 2-nitrovinylarenes
Okuro, Kazumi,Gurnham, Joanna,Alper, Howard
experimental part, p. 4715 - 4720 (2011/07/08)
Ionic diamine rhodium complex (1) catalyzes the reductive N-cyclization of 2-vinylnitroarenes using carbon monoxide as a reducing agent to afford functionalized indoles. The catalytic system allows direct access to indoles with ester and ketone groups at the 2- or 3-position, in good yields.
Sensitized two-photon photochemical deprotection
Pirrung, Michael C.,Dore, Timothy M.,Zhu, Yue,Rana, Vipul S.
scheme or table, p. 5313 - 5315 (2010/11/19)
The photoremovable protecting group NPPoc has little sensitivity to two-photon excitation, limiting its use in applications requiring high spatial control of its photochemistry. In the presence of a triplet sensitizer with a large two-photon absorption cross-section, however, the two-photon uncaging action cross-section is improved to levels useful in a variety of applications.
Amides as precursors of imidoyl radicals in cyclisation reactions
Bowman, W. Russell,Fletcher, Anthony J.,Pedersen, Jan M.,Lovell, Peter J.,Elsegood, Mark R.J.,Hernández López, Elena,McKee, Vickie,Potts, Graeme B.S.
, p. 191 - 203 (2007/10/03)
Amides have been successfully used as precursors of imidoyl radicals for radical cyclisation. The amides have been converted to imidoyl selanides via reaction with phosgene to yield imidoyl chlorides followed by reaction with potassium phenylselanide. Imidoyl selanides were reacted with tributyltin hydride (Bu3SnH) as the radical mediator with triethylborane or AIBN as initiators to yield imidoyl radicals for cyclisation reactions. Imidoyl radicals have been cyclised onto alkenes to yield 2,3-substituted-indoles and -quinolines and also onto pyrroles and indoles to give bi- and tricyclic heteroarenes.
