A facile and efficient synthesis of 1H‐indazoles and 1H‐pyrazoles through a copper‐promoted oxidative intramolecular C–H amination of hydrazones using a cleavable directing group was developed. This reaction is characterized by its mild conditions, operational simplicity, readily available reagents, and excellent yields. A tentative mechanism for Cu‐mediated C–H oxidative amination was proposed.

We have developed a protocol for the NaHSO3‐promoted esterification of sulfonyl hydrazides with alcohols for the synthesis of sulfinic esters. Various sulfonyl hydrazides could be converted to the corresponding sulfinic esters in good to high yields. The merits of this protocol include mild transition‐metal‐free reaction conditions, an inexpensive and available reagent, and operational simplicity. Controlled experiments reveal that this transformation probably undergoes via a radical pathway.

Reported here is the development of a novel, mild and practical protocol for the SO2F2‐promoted dehydroxylative fluorination of readily available alcohols. The advantages of this protocol include an inexpensive and available reagent, and operational simplicity. This method enables the transformation of many kinds of primary, secondary and tertiary (hetero) arene alcohols into the corresponding fluorides and tolerates a range of functional groups. And the reactions occur smoothly to give the desired products in moderate to high yields. And a tentative mechanism was proposed involving formation and elimination of key intermediate, sulfonyl ester.

A tunable and practical transformation of structurally diverse sulfonyl hydrazides into thiosulfonates in the presence of Rongalite (NaHSO2·CH2O) was developed. Transition-metal-free conditions, operational simplicity, and readily available reagents are the striking features of this protocol. It is the first example for the synthesis of thiosulfonates using sulfonyl hydrazides with the assistance of reductant. Additionally, the mechanistic studies revealed that this transformation probably undergoes via a reducing–coupling pathway.

A method for the synthesis of sulfinic esters was developed by using rongalite [CH 2 (OH)SO 2 Na] promoted esterification of sulfonyl chloride with alcohol. Various functional groups are compatible with the green strategy. It can be easily executed at gram level. Furthermore, mechanistic studies confirmed that this process can proceed via a radical mechanism. It represents a new method for green and efficient conversion of readily available sulfonyl chloride.