Manganese-catalyzed homogeneous hydrogenation of ketones and conjugate reduction of α,β-unsaturated carboxylic acid derivatives: A chemoselective, robust, and phosphine-free in situ-protocol

[Display omitted] •First Mn-catalyzed conjugate hydrogenation of cinnamate derivatives.•User-friendly and operationally simple in situ-system.•Glove-box-free, benchtop-compatible, and scalable catalytic protocol.•Broad functional group tolerance.•Cost-efficient and insensitive ligand. We communicate a user-friendly and glove-box-free catalytic protocol for the manganese-catalyzed hydrogenation of ketones and conjugated CCbonds of esters and nitriles. The respective catalyst is readily assembled in situ from the privileged [Mn(CO)5Br] precursor and cheap 2-picolylamine. The catalytic transformations were performed in the presence of t-BuOK whereby the corresponding hydrogenation products were obtained in good to excellent yields. The described system offers a brisk and atom-efficient access to both secondary alcohols and saturated esters avoiding the use of oxygen-sensitive and expensive phosphine-based ligands.