Abstract: Abifunctional amine/squaramide catalyst promoted direct aldol addition of an hydantoin surrogate to pyridine 2-carbaldehyde N-oxides to affordadducts bearing two vicinal tertiary/quaternary carbonsinhigh diastereo- and enantioselectivity (d.r.upto>20:1; ee up to 98%) is reported. Acid hydrolysis of adducts followedby reduction of the N-oxidegroup yields enantiopure carbinol-tethered quaternary hydantoin-azaarene conjugates with denselyfunctionalized skeletons. DFT studies of the potential energy surface (B3LYP/6–31+ G(d)+ CPCM (dichloromethane)) of the reaction correlate the activity of differentcatalysts and support an intramole cular hydrogen-bond-assisted activationofthe squaramide moiety in the transition state of the catalytic reaction.