132681-13-1Relevant articles and documents
Evaluation of 2-(piperidine-1-yl)-ethyl (PIP) as a protecting group for phenols: Stability to ortho-lithiation conditions and boiling concentrated hydrobromic acid, orthogonality with most common protecting group classes, and deprotection via Cope elimination or by mild Lewis acids
Norén, Rolf
, (2021/04/07)
A new protecting group, 2-(piperidine-1-yl)-ethyl (PIP), was evaluated as a protecting group for phenols. The PIP group was stable to ortho-lithiation conditions and refluxing with concentrated hydrobromic acid. Deprotection was accomplished by two routes, oxidation to N-oxides followed by Cope elimination (CE) and subsequent hydrolysis or ozonolysis of the vinyl ether or one-step deprotection by BBr3?Me2S. The PIP group is orthogonal to the O-benzyl, O-acetyl, O-t-butyldiphenylsilyl, O-methyl, O-p-methoxybenzyl, O-allyl, O-tetrahydropyranyl and N-t-butoxy carbonyl groups. The CE step was systematically studied and was found to give higher yields when the reaction was performed in the presence of silylating agents.
Design and synthesis of Sn-porphyrin based molecular gates
Guenet, Aurelie,Ernest Graf,Nathalie Kyritsakas,Hosseini, Mir Wais
scheme or table, p. 1872 - 1883 (2010/05/01)
The design, synthesis, and structural characterization, both in solution by 1H NMR and in the solid state by X-ray diffraction on single crystals, of a series of molecular gates based on Sn-porphyrin derivatives are presented. The molecular systemis based on a porphyrin core bearing at the meso positions either phenyl or pyridyl groups as a stator, octahedral Sn(IV) cation located at the center of the porphyrin as a hinge, and different handles connected to the porphyrin through Sn-O axial bonds. The stability of the complexes in the presence of different acids is also reported.
Ruthenium(III) acetylacetonate [Ru(acac)3] - An efficient chemoselective catalyst for the tetrahydropyranylation (THP) of alcohols and phenols under solvent-free conditions
Varala, Ravi,Adapa, Srinivas R.
, p. 1174 - 1179 (2007/10/03)
A catalytic amount of ruthenium(III) acetylacetonate (2 mol%) [Ru(acac)3] enables solvent-free tetrahydropyranylation of different types of alcohols and phenols at ambient temperature in moderate to excellent yields. Notably, selective monoprotection of diols can be achieved chemoselectively. Furthermore, the catalyst could be recovered and reused if necessary.
Strategies for the synthesis of bi- and triarylic materials starting from commercially available phenols
Chopa, Alicia B.,Silbestri, Gustavo F.,Lockhart, María T.
, p. 3865 - 3877 (2007/10/03)
A series of arylstannanes have been synthesized, through an SRN1 mechanism, in good to excellent yields (74%-99%) by the photostimulated reaction of trimethyl stannyl ion with substrates supporting different nucleofugal groups. The arylstannanes thus obtained were suitable intermediates for Stille cross-coupling reactions leading to asymmetric bi- and triaryl compounds in acceptable global yields. An attractive feature of this route is that simple commercially available benzenediols, chloro- and methoxy phenols might be useful starting substrates, leading the latter to higher global yields of products in fewer steps. The strategies proposed open a broad synthetic tool.
Studies of Chromenes. Part 9. Syntheses of Chromenequinones
Brown, Philip E.,Lewis, Robert A.,Waring, Mark A.
, p. 2979 - 2988 (2007/10/02)
Syntheses of 2,2-dimethylchromene-5,8-quinone, 2,2-dimethylchromene-6,7-quinone, and 6,7-dimethoxy-2,2-dimethylchromene-5,8-quinone are described.Being easily bioreductible to electron-rich chromenes these compounds, and their oxirane derivatives, are of
