Carbon–sulfur bonds widely exist in natural products, pesticides, and drugs, and their activation, cleavage, and transformation via transition metal catalysis have become more and more important in organic chemistry. During the past several decades, great progress on transition-metal catalyzed carbon–sulfur activation of thioesters and their transformations has been achieved. Carbon–sulfur bonds linking to both heteroaryl and aryl groups can be cleaved to construct carbon–carbon bonds by coupling reactions or to construct carbon–hydrogen bonds by reductions. This perspective is focused on recent advances in cleavage and transformations of transition-metal-catalyzed carbon–sulfur bonds.

Organoborane compounds are among the most commonly employed intermediates in organic synthesis and serve as crucial precursors to alcohols, amines, and various functionalized molecules. A simple palladium-based system catalyzes the conversion of primary C(sp(3) )H bonds in functionalized complex organic molecules into alkyl boronate esters. Amino acids, amino alcohols, alkyl amines, and a series of bioactive molecules can be functionalized with the use of readily available and removable directing groups in the presence of commercially available additives, simple ligands, and oxygen (O2 ) as the terminal oxidant. This approach represents an economic and environmentally friendly method that could find broad applications.

Fluorenes are a commonly encountered structural motif in materials science, pharmaceutical chemistry, and organic synthesis. Among various strategies towards the synthesis of this unique structure, transition metal-catalyzed functionalization has emerged as one of the most efficient methods. This Minireview presents an overview of the recent advances in this emerging area by highlighting the reactions' specificity and applicability and, where possible, provides a mechanistic rationale.

It still remains a major challenge to apply free primary amino groups as the directing group for aliphatic C–H functionalization.