In recent years, phenol derivatives have emerged as powerful alternatives to aryl halides as coupling partners in cross-coupling reactions due to their relative lack of toxicity and widespread availability. Despite the significant advances achieved, the vast majority of C–O bond cleavage methodologies involves the use of particularly activated functionalities, such as triflates, whereas unactivated aryl esters or ethers have been mainly employed in limited C–C bond-forging processes. These doctoral studies have been focused on methods to achieve the formation of C–heteroatom bonds, namely C–Si and C–B bonds, by means of Ni-catalyzed activation of these unconventional C–O electrophiles.