Selective Photodeprotection Modulated by the Sunscreen Effect

Or Eivgi, Chemistry, Ben-Gurion Unviersity of the Negev, Beer Sheva, Israel

Photolabile protecting groups (PPGs) are a powerful tool for synthetic applications due to their simple cleavage and compatibility with most functional groups. The deprotection of two different PPGs in a single scheme requires 'chromatic orthogonality' and fine tuning between the chromophore properties and reaction kinetics. Bochet et al. developed this concept and showed that selective deprotection of PPGs can be achieved by irradiating with light at different wavelengths.¹

In this work we show our preliminary results on a novel type of chromatic selectivity by exploiting differences in molar absorption coefficients of different PPGs at single wavelengths. This appealing strategy can be used with internal or external auxiliary chromophores that absorb light and function as a "sunscreens" for one of the PPGs, prompting the selective deprotection at a single wavelength.

 

References: 

1. (a) Aure´lien Blanc and Christian G. Bochet, Organic Letters, 2007, 9, 2649; (b) Emmanuel Riguet and Christian G. Bochet, Organic Letters, 2007, 9, 5453; (c) Tomáš Šolomek, Sébastien Mercier,Thomas Bally and Christian G. Bochet, Photochem. Photobiol. Sci., 2012, 11, 548.