Disclosed are novel 4-alkenyl- and 4-alkynyl oxindoles having the formula ##STR1## and the pharmaceutically acceptable salts thereof, wherein R.sup.1, R.sup.2, R.sup.3, a, b, and X are as defined herein. These compounds inhibit cyclin-dependent kinases (CDKs), in particular CDK2. These compounds and their pharmaceutically acceptable salts, and prodrugs of said compounds, are anti-proliferative agents useful in the treatment or control of cell proliferative disorders, in particular cancer, more particularly, the treatment or control of breast and colon tumors. Also disclosed are pharmaceutical compositions containing the compounds of formula I and II as well as intermediates useful in the preparation of the compounds of formula I and II.

É divulgada a novela 4-alkenyl- e os oxindoles 4-alkynyl que têm o ## do ## STR1 da fórmula e os sais pharmaceutically aceitáveis disso, wherein R.sup.1, R.sup.2, R.sup.3, a, b, e X são como definidos nisto. Estes compostos inibem os kinases cyclin-dependentes (CDKs), em CDK2 particular. Estes compostos e seus sais pharmaceutically aceitáveis, e os prodrugs de compostos ditos, são agentes antiproliferativos úteis no tratamento ou no controle de disorders proliferative da pilha, no cancer particular, mais particularmente, no tratamento ou no controle do peito e dos tumors dos dois pontos. São divulgadas também as composições pharmaceutical que contêm os compostos da fórmula I e II as.well.as os intermediários úteis na preparação dos compostos da fórmula I e II.