The ubiquity of carbon halogen bonds in the structural core of numerous biomolecules and pharmaceuticals along with their role as synthetic precursors in various organic reactions makes the organic halides a crucial class of organic compounds. Consequently, the synthesis of organic halides with high regioselectivity is of paramount importance in synthetic chemistry. In nature, selective halogenation is achieved by metalloenzymes with high efficiency involving high-valent iron-oxo as active species. The high selectivity of halogenating enzymes attracted considerable attention leading to the development of several biomimetic approaches for CÀ H halogenation. Moreover, the emergence of transition metal (TM) catalyzed site-selective CÀ H halogenation protocols through the development of several directed strategies has also been impressive. There has been significant development in the first row TM catalyzed CÀ H halogenation reactions despite the dominance of late transition metals catalysts in this field. But in literature, there is no up-to-date recent review article that consolidates bio-mimetic as well as synthetic strategies of CÀ H halogenation (X = Cl, Br, I) containing organo-fluorination with all the first-row transition metals. Thus, we got motivated and have focused to elucidate the recent developments of first row TM-catalyzed CÀ H halogenation of (hetero)arenes and alkanes through biomimetic approaches as well as directed and undirected strategies in this present review. Additionally, this review covers the recent progresses in the CÀ H fluorination methodologies. Altogether, the review will provide a combined overview of all the strategies of first-row transition-metalmediated CÀ H halogenation reactions that may benefit the scientific community towards the development of new methodologies in this field.

Palladium‐pincer complexes containing monoanionic, tridentate pincer ligand have evolved as a privileged synthetic tool that can be applied in different fields of research including material science and synthetic organic chemistry such as cross‐coupling, hydrophosphination, and allylation reaction. Among them, CH bond activation is one of the most efficient, convenient, and greener approach due to its ability to perform corresponding functionalization from easily available and naturally abundant feedstock. However, number of the reports solely highlighting the application of Pd‐pincer complexes in CH activation is very less. In this article, we have discussed the synthesis of Pd‐pincer complexes via CH bond activation followed by their useful application in the field of CH bond activation.

Ruthenium‐catalyzed direct C(sp 2 )H bond amidation has emerged as a convenient synthetic tool for the synthesis of bioactive and active pharmaceutical molecules. Different directing groups (DGs) including hetero‐arenes, carbonyl groups are used for ortho ‐ amidations that lead to the synthesis of functionalized amine and amides. The easily removable methyl‐phenyl sulfoximine (MPS) has been found to be very effective in case of carboxylic acids whereas transient DG strategy was effective for weakly coordinating benzaldehydes. These methods have been applied for the synthesis of important life‐saving drug molecules. In this article, we have discussed the ruthenium‐catalyzed direct amidation of C(sp 2 )H bonds of arenes with mechanistic elucidations.