rahaas, I couldn't do them that way at first either. What saved me was the "Poliquin strap trick":
Poliquin strap trick for front squats
u-tube demo of someone using them for a 500-lb front squat
I used that strap trick for over a year before my wrists became flexible enough to do my fronts strapless (yes, that DID sound sexier than it actually is...). I found my wrist flexibility just sorta happened over time, just from holding the straps. I still use them for my heavier fronts - anything heavier than about 155 and my elbows start to drop. I imagine this will improve actuarially, but in the meantime I'll continue to employ the straps.
Will Brink suggests another option for fronts - instead of bending the wrists backward, try palms down:
u-tube demo of Brink Front Squats - alternative grip for people who have problems with clean or arms crossed grips