The mechanistic models so far proposed to explain the behavior of vinylsulfoxides as dienophiles in asymmetric Diels-Alder reactions are revised on the basis of the results obtained in the reactions of (S)-benzyl 2-p-tolylsulfinylacrylate 3 with cyclopentadiene, Dane's diene and furan under different conditions, as well as other results previously reported, concerning sulfinylacrylates, sulfinylmaleates and trialkoxycarbonyl sulfinyl ethenes. The moderate reactivity of sulfinylacrylates and the scarce influence that the incorporation of additional alkoxycarbonyl groups exerts on their reactivity is explained by assuming a variable electronic influence of the sulfinyl group on the double bond, acting as withdrawing and donating electron group depending on the substitution at the double bond. In the reactions with cyclopentadiene, both reactivity and stereoselectivity raised in the presence of ZnX2 as catalysts (ZnI2>ZnBr2>ZnC12), but TiCI 4 was found to be the most efficient catalyst allowing the reactions to take place at low temperatures. With cyclopentadiene and furan, steric and electronic interactions between the CH2 and O, respectively, and the substituent at sulfur on the s-cis conformation of the vinylsulfoxide must be considered to predict the favored stereochemical course.