Herein, for the first time, a metal-organic framework (MOF) is reported as a catalyst for α-alkylation of ketones with alcohols. Using an encapsulation strategy via nano-confinement of a homogeneous Mn-phenanthroline complex into MOF pores, functionalized branched ketones were selectively produced. Mechanistic investigations and deuterium labelling experiments validated the utilization of the borrowing hydrogen strategy. The formation of extra Lewis acid sites, defects, and pore enhancement during catalysis helped in achieving higher activity and selectivity.