The unique steric effect of geminal bis(silane) [(R3Si)(2)CH] allows an exo-selective intermolecular Diels-Alder reaction of geminal bis(silyl) dienes with alpha,beta-unsaturated carbonyl compounds. The approach shows good generality to form ortho trans cydohexenes in good yields with high exo-selectivity and high enantioselectivity in some asymmetric cases. The excellent exo-stereocontrol aptitude of (R3Si)(2)CH group is highlighted by comparing with R3SiCH2 and R3Si groups, which leads to endo-selectivity predominantly. The conformational analysis of dienes suggests that (R3Si)(2)CH group effectively shields both sides of the diene moiety, ensuring the desired exo-selectivity. Moreover, the geminal bis(silane) can be further functionalized to transform the resulting ortho trans cycloadducts into useful synthons, which makes the approach hold great potential for organic synthesis.