Scheme 4. Early examples of intramolecular asymmetric reductive amination reactions enabled by IREDs at high amine: ketone ratios.^49,55 (m.e. = molar equivalents). ‘NADPH’ in this and other schemes signifies the requirement of this reduced cofactor for the reaction, and is usually generated with the assistance of a cofactor recycling system comprising e.g. glucose dehydrogenase (GDH) and glucose, omitted from this and other schemes.