457612-05-4Relevant academic research and scientific papers
Isotope effects in photochemistry: Application to chromatic orthogonality
Blanc, Aurelien,Bochet, Christian G.
, p. 2649 - 2651 (2008/02/08)
Equation Presented The main challenge in developing new wavelength-specific photolabile protecting groups is the rigorous control of the photolysis rate. This rate is controlled by two factors: the chromophore absorbance and the reaction quantum yield. Fine-tuning the properties by changing substituents or structural features is difficult, because both factors are independently affected. By the use of the kinetic isotope effect, we could tune the quantum yield without altering the absorbance, and hence control the overall reaction rate. We exemplified this approach with chromatically orthogonally protected diesters.
Isotope effects in photochemistry. 1. o-nitrobenzyl alcohol derivatives
Blanc, Aurelien,Bochet, Christian G.
, p. 7174 - 7175 (2007/10/03)
The photolysis of o-nitrobenzyl alcohol derivatives shows a strong kinetic isotope effect (KIE up to 8.3) at the benzylic center. For some derivatives, the KIE is wavelength dependent, suggesting the involvement of higher excited states. In addition to th
Wavelength-controlled orthogonal photolysis of protecting groups
Blanc, Aurelien,Bochet, Christian G.
, p. 5567 - 5577 (2007/10/03)
The selective control of a chemical process by the use of an electromagnetic wave has been a challenging goal for several decades. In this article, we describe for the first time the use of a monochromatic light beam to differentiate two different reactive centers. A direct application of this concept is found in the chemistry of protecting groups. Two different photolabile protecting groups were tuned to be responsive to a specific wavelength (e.g., 254 or 420 nm). Using derivatives of the 2-nitroveratryl fragment (such as 10, sensitive at 420 nm) and 3′,5′-dimethoxybenzoin fragment (such as 4, sensitive at 254 nm), it was shown that energy transfer phenomena did not erode the selectivity. Both the inter- and the intramolecular cases were studied and showed selectivities within the synthetically useful range. Hence, we could replace the traditional chemical orthogonality by a chromatic orthogonality.
