The synthesis of several diblock copolymers with DMAEMA via anionic polymerization is presented; PS-b-PDMAEMA, PB-b-PDMAEMA, poly(p-tert-butoxystyrene)-b-PDMAEMA, and PEO-b-PDMAEMA. The latter was synthesized using sec-butyllithium as initiator in presence of the phosphazene base t-BuP4, enabling a facile changeover from an oxyanion to a carbanion. All reactions resulted in narrowly distributed block copolymers (PDI < 1.1). For PEO-b-PDMAEMA, diblock copolymers with a high blocking efficiency and a near-narrow molecular weight distribution (PDI < 1.40) could be prepared. The advantage of the presented one-pot synthesis is a significant higher blocking efficiency compared to commercially available PEO macroinitiators under similar conditions.