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We observed 5 gamma-ray loud blazars at redshift greater than 2 with theX-Ray Telescope (XRT) and the UltraViolet and Optical Telescope (UVOT) onboardthe Swift satellite, and the Gamma-Ray burst Optical Near-Infrared Detector(GROND) instrument. These observations were quasi simultaneous, usually withina few hours. For 4 of these blazars the near-IR to UV data show the presence ofan accretion disc, and we could reliably estimate its accretion rate and blackhole mass. One of them, PKS 1348+007, was found in an extraordinarily highIR-optical state, almost two orders of magnitude brighter than at the epoch ofthe Sloan Digital Sky Survey observations. For all the 5 quasars the physicalparameters of the jet emitting zone, derived by applying a one-zone emissionmodel, are similar to that found for the bulk of other gamma-ray loud quasars.With our observations we have X-ray data for the full sample of blazars at z>2present in the Fermi 2-yrs (2LAC) catalog. This allows to have a rathercomplete view of the spectral energy distribution of all high-redshift Fermiblazars, and to draw some conclusions about their properties, and especiallyabout the relation between the accretion rate and the jet power.

High redshift Fermi blazars observed by GROND and Swift