The transition metal-catalyzed asymmetric α-arylation of aldehydes is an highly challenging transformation in the synthetic chemistry. The α-arylated aldehydes are important structural motifs in many biologically and pharmaceutically active molecules. However, there are only few protocols available for the synthesis of α-arylated aldehydes. The main aim of this thesis is to find the suitable reaction conditions for the non-asymmetric and asymmetric α-arylation of aldehydes. In the first part of thesis, we have developed a [Pd(NHC)]-catalyzed intermolecular α-arylation of linear and α-branched aldehydes with aryl bromides. We have also reported the unusual α-arylative esterification of α-branched aldehydes and acylation of aryl bromide with linear aldehyde with same catalyst. In the second part of thesis, we describe the synthesis of novel atropoisomeric (P,N)-ligands and their application in the Pd-catalyzed asymmetric α-arylation of α-branched aldehydes. Under the optimized conditions, the enantio-enriched α-arylated aldehydes were obtained in good yields with excellent levels of enantioselectivities.