Wavelength-Controlled Orthogonal Photolysis of Protecting Groups

• Published in: Journal of organic chemistry Vol. 67; no. 16; pp. 5567 - 5577
• Main Authors: Blanc, Aurélien, Bochet, Christian G
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 09.08.2002; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Exact sciences and technology; General and physical chemistry; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Physical Sciences; Science & Technology; PHOTOCHEMISTRY; SAFETY-CATCH LINKER; EXCITATION; CLEAVAGE; ESTERS; Nitro compound; Protecting group; Photolysis; Aromatic compound; Selectivity; Light absorption; Photochemical reaction; Energy transfer
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo025837m

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.