✍ Scribed by Griesbeck, Axel G.
No coin nor oath required. For personal study only.
Amino acids whose amino groups are transformed into phthalimido chromophores are versatile substrates for photochemical transformations such as cyclization, isomerization, and β‐cleavage. These processes are initiated by homolytic or mesolytic CH activation and depend on the spin state of the excited substrate. Derivatives of α‐amino acids without strong electron‐donating substituents [Abu, Nva, Val, Leu, Ile, Tle, Phe, Met(SO)] react by initial homolytic CH activation and solely via their first excited singlet states, whereas substrates with strong electron‐donating substituents (Tyr, DOPA, Met, Glu, Asp) react by initial photoinduced electron transfer (PET) followed by mesolytic CH activation and solely via their first excited triplet states. The S‐alkyl cysteine derivatives are the only ones which show competing singlet and triplet state reactivity with pronounced spin‐determined regioselective CH activation. The amino dicarboxylic acids Glu and Asp could be applied as the carboxylates in PET reactions, a strategy which also opened up a new synthetic approach to medium‐ and large‐ring systems.
📜 SIMILAR VOLUMES
Several synthetic /J,f-unsaturated &amino acids have recently been developed as specific irreversible inhibitors of pyridoxal l,hosl,hate dependent enzymes. 1 A few naturally occurring P,d-unsaturated amino acids are known to function as specific enzyme inhibitors 2. including rhizobitoxine inhibiti