25559-38-0Relevant articles and documents
Ability of the Putative Decomposition Products of 2,3-dioxetanes of Indoles to Photosensitize Cyclobutane Pyrimidine Dimer (CPD) Formation and its Implications for the “Dark” (Chemisensitized) Pathway to CPDs in Melanocytes?
Cacchillo, Elena M.,Niedzwiedzki, Dariusz M.,Taylor, John-Stephen,Wang, Yanjing
, (2021/10/14)
The formation of cyclobutane pyrimidine dimers (CPDs) by a “dark” pathway in melanocytes has been attributed to chemisensitization by dioxetanes produced from peroxynitrite oxidation of melanin or melanin precursors. These dioxetanes are proposed to decompose to triplet state compounds which sensitize CPD formation by triplet–triplet energy transfer. To determine whether such compounds are capable of sensitizing CPD formation, the putative decomposition products of 2,3-dioxetanes of variously substituted indoles were synthesized and their triplet state energies determined at 77?K. Their ability to photosensitize CPD formation was determined by an enzyme-coupled gel electrophoresis assay in comparison with norfloxacin (NFX) which has the lowest triplet energy known to sensitize CPD formation. The decomposition products of 2,3-dioxetanes of 5-hydroxy and 5,6-dimethoxy indoles used as models for melanin precursors had lower triplet energies and were incapable of photosensitizing CPD formation. Theoretical calculations suggest that the decomposition products of the 2,3-dioxetanes of melanin precursors DHI and DHICA will have similarly low triplet energies. Decomposition products of the 2,3-dioxetanes of indoles lacking oxygen substituents had higher triplet energies than NFX and were capable of photosensitizing CPD formation, suggesting that peroxynitrite oxidation of tryptophan could play a hitherto unrecognized role in the dark pathway to CPDs.
PPTS-Catalyzed Bicyclization Reaction of 2-Isocyanobenzaldehydes with Various Amines: Synthesis of Diverse Fused Quinazolines
Meng, Xiang-He,Wu, Dan-Ni,Zhang, Yu-Jia,Zhao, Yu-Long
supporting information, p. 1923 - 1929 (2021/02/26)
A PPTS (pyridinium p-toluenesulfonate)-catalyzed bicyclization reaction of 2-isocyanobenzaldehydes as 1,5-dielectrophiles with various amines has been developed. The reaction not only provides a simple and efficient strategy for the assembly of structurally diverse fused quinazoline derivatives from readily available substrates under metal-free and mild conditions in a single step with only water and hydrogen as the by-products, but also opens the way to the application of o-formyl arylisocyanides in the synthesis of nitrogen-containing heterocycles. (Figure presented.).
ortho-Lithiophenyl isocyanide: A versatile precursor for 3H-quinazolin-4-ones and 3H-quinazolin-4-thiones
Lygin, Alexander V.,De Meijere, Armin
supporting information; experimental part, p. 389 - 392 (2009/09/05)
(Chemical Equation Presented) ortho-Lithiophenyl isocyanide has been generated from ortho-bromophenyl isocyanide and successfully employed toward the synthesis of 2-substituted phenyl Isocyanides as well as 2,3-disubstituted 3H-quinazoline-4-ones and 3H-q
