Synthesis of fused 3-amino-1,2,4-triazoles via sequential addition of aryl hydrazines to isothiocyanates and I 2 -mediated cyclodesulfurization

Iodine-Catalyzed Synthesis of Benzo-β-carbolines through Desulfurative Cyclization of 2-(1H-Indol-3-ylsulfanyl)-phenylamines with Aryl Methyl Ketones

A novel transition metal-free strategy for the synthesis of benzene-fused β-carboline scaffolds has been developed. This protocol offers a rapid and direct pathway to access the benzene fused β-carboline from 2-(1H-indol-3-ylsulfanyl)-phenylamines and aryl methyl ketones using an efficient catalytic system of I2/DMSO. The present mild protocol proceeds through the sequential reactions of Kornblum oxidation, Pictet-Spengler cyclization, and desulfurization to afford the desired products in excellent yields up to 99%. Moreover, this method has a wide range of substrate tolerance and is operationally simple and applicable in gram-scale synthesis.

Access to 3-Amino-[1,2,4]-triazolo Pyridines and Related Heterocycles via Electrochemically Induced Desulfurative Cyclization

An efficient, one-pot approach has been established for synthesizing a wide range of 3-amino-[1,2,4]-triazolo pyridines and related heterocycles from the electrochemically induced desulfurative cyclization of 2-hydrazinopyridines with isothiocyanates. The protocol allows for the formation of C-N bonds under simple conditions without transition metals or external oxidants. The practicability of this strategy is demonstrated by its broad substrate scope, good functional group compatibility, and gram-scale synthesis. The late-stage modification of 3-amino-[1,2,4]-triazolo pyridines enables us to obtain several molecules with potent anticancer activity.

I2-Catalyzed oxidative synthesis of N,4-disubstituted quinazolines and quinazoline oxides

An easy and efficient approach to the synthesis of N,4-disubstituted quinazoline-2-amine and oxides is described. This transformation proceeds smoothly in the presence of molecular iodine. The metal-free protocol presented here is insensitive to air moisture and operationally simple. This versatile and synthetic methodology is broadly applicable to a variety of N,4-disubstituted quinazoline-2-amines and oxides, which are synthesized in good to excellent yields starting from readily available inexpensive precursors.