Aromatic molecules represent an attractive class of feedstock compounds for organic synthesis because of their ready availability, their stability, and the wealth of classical and modern chemistry available for their preparation and manipulation. The development of enantioselective, catalytic methodologies that engage aromatic p systems as substrates offers particular promise for synthetic applications. Despite this potential, it is only recently that aromatic frameworks have been employed successfully as electrophiles [1] or nucleophiles [2] in asymmetric, catalytic reactions, and many important challenges in this area remain unmet. The addition of carbon-centered nucleophiles to nitrogen-containing heteroaromatic compounds is a particularly interesting problem, in light of the potential impact of such a methodology on alkaloid synthesis. Diastereoselective reactions controlled by chiral auxiliaries currently constitute the state-of-the-art methods for the majority of stereocontrolled transformations of this type. [3] The elegant alkaloid syntheses of Comins et al. based on diastereoselective nucleophilic additions to chiral (4-methoxy)acylpyridinium derivatives illustrate the utility of such approaches. [4] Only one enantioselective, catalytic method for the addition of carbon-centered nucleophiles to aromatic nitrogen heterocycles has been developed to date: the aluminum-catalyzed acylcyanation of quinolines, isoquinolines, and pyridines (the Reissert reaction) developed by Shibasaki and co-workers. [1a-d] Herein, we report the first example of an asymmetric, catalytic addition of enolate equivalents to heteroaromatic electrophiles. This acyl-Mannich reaction, [5] catalyzed by a chiral thiourea derivative, provides access to useful enantioenriched dihydroisoquinoline building blocks. [6] N-Alkylations or N-acylations of nitrogen-containing heteroaromatic compounds give rise to highly electrophilic