Photosensitized selective semi-oxidation of tetrahydroisoquinoline: a singlet oxygen path

Autor: Mahzad Yaghmaei, Martin Villanueva, Iris Martín-García, Francisco Alonso, Xiaocong Zhang, Neeraj Joshi, Anabel E. Lanterna, Juan C. Scaiano
Přispěvatelé: Universidad de Alicante. Departamento de Química Orgánica, Universidad de Alicante. Instituto Universitario de Síntesis Orgánica, Nuevos Materiales y Catalizadores (MATCAT)
Rok vydání: 2022
Předmět:
Zdroj: Photochemical & Photobiological Sciences. 21:1473-1479
ISSN: 1474-9092
DOI: 10.1007/s43630-022-00237-9
Popis: Selective semi-oxidation of tetrahydroisoquinoline (THIQ) leads to a valuable dihydroisoquinoline (DHIQ) derivative via singlet oxygen photooxidation process. Typical photosensitisers (i.e., Ru complexes) can activate the reaction even under heterogeneous conditions that facilitate catalyst separation and reusability. In contrast to DHIQ, THIQ acts as an efficient singlet oxygen quencher driving the reaction selectivity. The reaction can also be facilitated by semiconductor catalysts such as MoCo@GW, a glass wool-based catalyst that is easy to separate and reuse and compatible with flow photochemistry. Its role is to mediate the formation of isoquinoline (IQ) and thus an in situ-generated singlet oxygen catalyst. Laser flash photolysis with NIR detection provides proof of the singlet oxygen mechanism proposed and rate constants for the key steps that mediate the oxidation. This work was supported by the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, and the Canada Research Chairs Program. We also thank the Spanish Ministerio de Ciencia e Innovación (MCIN; grant no. CTQ2017-88171-P) and the Generalitat Valenciana (GV; grant no. AICO/2017/007) for financial support.
Databáze: OpenAIRE