Although the growth of structure, as traced by galaxy clusters, has been extensively studied through cosmological simulations and large-scale surveys, the early formation and evolution of their galaxy content, and its relation to the transformation of the host environment, are still somewhat poorly understood. This is particularly true of the processes that give rise to the quiescent galaxy population between z=3 and z=2. Recent discoveries at z~2 are now bridging the gap between the well-established massive clusters of the last 9 Gyr and the high-redshift universe, and new datasets are now giving us access to statistical populations of intermediate-mass structures at this epoch. I will discuss the properties of quiescent galaxies in the most distant confirmed X-ray detected galaxy clusters, their implications for galaxy quenching at high-redshift as well as the regulation of star formation at group scales at z~2.