Buchwald–Hartwig reaction: an update

Carbon–nitrogen cross-coupling reaction is an imperative and vital conversion in organic synthesis since one of its products, arylamines, are key frameworks in several natural products, pharmaceuticals, and other biologically active compounds. For the development of such important C–N coupling reaction, Buchwald and Hartwig made noteworthy contributions by presenting a plethora of ligands in addition to the conventional Pd and Cu catalysts. In this review, we try to update our previous review, covering the recent progresses in applications of Buchwald–Hartwig reaction in organic reactions, in the synthesis of heterocyclic compounds and total synthesis of natural products. This review covers this important advancement from 2018 till date. Graphic abstract