Insight into drilling performance parameters for in-situ detection of lithological transition.

In order to examine the rock dependence on drilling performance parameters, such as torque and rate of penetration (ROP), we conducted laboratory drilling experiments using mafic and ultramafic rocks from the Oman ophiolite and the Horoman Complex. Serpentinized peridotite shows approximately twice the ROP (dry conditions: 2.95 ~ 3.

Aerobic Oxidative C-H Azolation of Indoles and One-Pot Synthesis of Azolyl Thioindoles by Flavin-Iodine-Coupled Organocatalysis.

The aerobic oxidative cross-coupling of indoles with azoles driven by flavin-iodine-coupled organocatalysis has been developed for the green synthesis of 2-(azol-1-yl)indoles. The coupled organocatalytic system enabled the one-pot three-component synthesis of 2-azolyl-3-thioindoles from indoles, azoles, and thiols in an atom-economical manner by utilizing molecular oxygen as the only sacrificial reagent.

Multicomponent Synthesis of Imidazo[1,2-]pyridines: Aerobic Oxidative Formation of C-N and C-S Bonds by Flavin-Iodine-Coupled Organocatalysis.

Herein, we report an aerobic oxidative C-N bond-forming process that enables the facile synthesis of imidazo[1,2-]pyridines and takes advantage of a coupled organocatalytic system that uses flavin and iodine. Furthermore, the dual catalytic system can be applied to the one-pot, three-step synthesis of 3-thioimidazo[1,2-]pyridines from aminopyridines, ketones, and thiols.

Aerobic Oxidative Sulfenylation of Pyrazolones and Pyrazoles Catalyzed by Metal-Free Flavin-Iodine Catalysis.

Two-component metal-free catalytic oxidative sulfenylation of pyrazolones with thiols has been achieved using the biomimetic flavin and iodine. The methodology is mild and eco-friendly, proceeds in the presence of air or molecular oxygen (1 atm) as the sole sacrificial reagent, and generates water as the only byproduct. The methodology was also extended to the sulfenylation of pyrazoles and electron-rich benzenes and afforded a series of thioethers in good yields.