- De novodesign and synthesis of dipyridopurinone derivatives as visible-light photocatalysts in productive guanylation reactions
-
Described here is thede novodesign and synthesis of a series of 6H-dipyrido[1,2-e:2′,1′-i]purin-6-ones (DPs) as a new class of visible-light photoredox catalysts (PCs). The synthesizedDP1-5showed theirλAbs(max)values in 433-477 nm, excited state redox potentials in 1.15-0.69 eV and ?1.41 to ?1.77 eV (vs.SCE), respectively. As a representative,DP4enables the productive guanylation of various amines, including 1°, 2°, and 3°-alkyl primary amines, secondary amines, aryl and heteroaryl amines, amino-nitrile, amino acids and peptides as well as propynylamines and α-amino esters giving diversities in biologically important guanidines and cyclic guanidines. The photocatalytic efficacy ofDP4in the guanylation overmatched commonly used Ir and Ru polypyridyl complexes, and some organic PCs. Other salient merits of this method include broad substrate scope and functional group tolerance, gram-scale synthesis, and versatile late-stage derivatizations that led to a derivative81exhibiting 60-fold better anticancer activity against Ramos cells with the IC50of 0.086 μM than that of clinical drug ibrutinib (5.1 μM).
- Gao, Wenjing,Ma, Nana,Wan, Yameng,Wu, Hao,Zhang, Guisheng,Zhang, Zhiguo,Zhao, Jie
-
p. 15988 - 15997
(2021/12/30)
-
- Guanidine Synthesis: Use of Amidines as Guanylating Agents
-
The use of amidines for the tandem or one-pot synthesis of guanidines is reported. Guanidines are obtained by oxidative rearrangement of readily available and stable amidines into carbodiimides, followed by in situ reaction with amines. The protocol can be executed under mild reaction conditions (30°C), in a green solvent (dimethyl carbonate). The amine scope is broad, including sterically hindered, oxidation-sensitive and chiral amines. Examples for the synthesis of both acyclic and cyclic guanidines are provided. 2-Propoxyphenyl iodide (2-PrOPhI) by-product, generated from the oxidant [N-(p-toluenesulfonyl)imino](2-propoxyphenyl)iodinane (2-PrOPhINTs), can be isolated in high yields making regeneration of the hypervalent iodine reagent possible. The utility and greenness of the synthetic method versus the state-of-the-art is demonstrated by a new route towards the antihypertensive drug Pinacidil. The process mass intensity (PMI) of the new route is only 24% of the classical one.
- Baeten, Mattijs,Maes, Bert U. W.
-
p. 826 - 833
(2016/03/12)
-
