We present BeppoSAX observations of three gamma -ray-emitting quasars, name
ly, 0836+710, 1510-089, and 2230+114. The three objects have been detected
up to similar to 100 keV showing extremely hat power-law spectra above 2 ke
V (energy index alpha (2-10) = 0.3-0.5). The soft X-ray spectrum of 0836+71
0 implies either an absorption column density higher than the Galactic one
or an intrinsically very hard slope (alpha (0.1-1) = -0.2) below 1 keV. 151
0-089 shows a soft excess, with the low-energy spectrum steeper (alpha (0.1
-1) = 1.6) than the high-energy power law. The results are discussed in the
framework of current inverse Compton models for the high-energy emission o
f hat-spectrum radio quasars and are used to estimate the physical quantiti
es in the jet-emitting region and to shed light on the energy transport mec
hanisms in jets. Finally we discuss the estimates of the jet luminosity in
the context of the Blandford & Znajek mechanism for jet production.