Organic compounds containing amino groups are one of the most important classes of chemicals in both academia and industry. This class of materials is a very important structural motif in organic synthesis due to its widespread applications in natural products, agrochemicals, pharmaceuticals, and advanced materials. This book is a concise overview of modern approaches to N-alkylation and N-arylation of primary, secondary and tertiary amines using alkylating and arylating reagents with amino sources found in both basic and applied chemical research. The work also discusses key examples of amine synthesis from a sustainable perspective, using deep eutectic solvents and the application of amines in different areas. It is an ideal reference for advanced and postgraduate students as well as academic and industrial chemists working in organic, natural product, catalytic, medicinal, and polymer chemistry.