845504-46-3Relevant articles and documents
PHP-Tethered N-Acyl Carbamate: A Photocage for Nicotinamide
Salahi, Farbod,Purohit, Vatsal,Ferraudi, Guillermo,Stauffacher, Cynthia,Wiest, Olaf,Helquist, Paul
supporting information, p. 2547 - 2550 (2018/05/22)
The synthesis of a new photocaged nicotinamide having an N-acyl carbamate linker and a p-hydroxyphenacyl (pHP) chromophore is described. The photophysical and photochemical studies showed an absorption maximum at λ = 330 nm and a quantum yield for release of 11% that are dependent upon both pH and solvent. While the acyl carbamate releases nicotinamide efficiently, a simpler amide linker was inert to photocleavage. This photocaged nicotinamide has significant advantages with respect to quantum yield, absorbance wavelength, rate of release, and solubility that make it the first practical example of a photocaged amide.
A facile mild deprotection protocol for 1,3-dithianes and 1,3-dithiolanes with 30% hydrogen peroxide and iodine catalyst in aqueous micellar system
Ganguly, Nemai C.,Barik, Sujoy Kumar
experimental part, p. 1393 - 1399 (2009/12/29)
A simple clean expeditious protocol for the deprotection of 1,3-dithianes and 1,3-dithiolanes has been developed using 30% aqueous hydrogen peroxide activated by iodine catalyst (5 mol%) in water in the presence of sodium dodecyl sulfate (SDS) under essentially neutral conditions. The method showed tolerance for a number of phenol protecting groups such as allyl, benzyl, TBDMS, TBDPS ethers, phenolic acetates, and benzoates as well as amino-protecting BOC, Cbz carbamates without any detectable overoxidation. Georg Thieme Verlag Stuttgart.
Ultrafast time-resolved transient absorption and resonance Raman spectroscopy study of the photodeprotection and rearrangement reactions of p-hydroxyphenacyl caged phosphates
Ma, Chensheng,Kwok, Wai Ming,Chan, Wing Sum,Du, Yong,Kan, Jovi Tze Wai,Toy, Patrick H.,Phillips, David Lee
, p. 2558 - 2570 (2007/10/03)
The kinetics and mechanism of the photodeprotection and rearrangement reactions for the pHP phototrigger compounds p-hydroxyphenacyl diethyl phosphate (HPDP) and diphenyl phosphate (HPPP) were studied using transient absorption (TA) and picosecond time-resolved resonance Raman (ps-TR3) spectroscopy. TA spectroscopy was employed to detect the dynamics of the triplet precursor decay as well as to investigate the influence of the solvent and leaving group on the triplet quenching process. Ps-TR3 spectroscopy was used to directly monitor the formation dynamics for the photosolvolytic rearrangement product and its solvent and leaving group dependence. The TA and TR3 spectroscopy experiments were also used to characterize the structural and electronic properties of the triplet precursor to the HPDP and HPPP deprotection reactions. The solvent effect observed in conjunction with the leaving group dependence of the triplet decay dynamics are consistent with a concerted solvent assisted triplet cleavage through a heterolytic mechanism for the HPDP and HPPP photodeprotection process. Correlation of the dynamics between the deprotection and rearrangement processes reveals there is a consecutive mechanism and the involvement of an intermediate between the two reaction steps. The reaction rate of the deprotection and rearrangement steps and the influence of the solvent and leaving group were determined and evaluated based on kinetic modeling of the dynamical data obtained experimentally for HPDP and HPPP in H2O/MeCN mixed solvents with varying water concentration in the solvent system. A solvation complex with a contact ion pair character was proposed to be the intermediate involved in the deprotection and rearrangement pathway. The results here combined with our previous study on the photophysical events occurring on the early picosecond time scale (Ma; et al. J. Am. Chem. Soc. 2005, 127, 1463-1472) provide a real time overall mechanistic description for the photodeprotection and rearrangement reactions of pHP caged phosphate phototrigger compounds.
