Minimum voltage for a RC Oscillator
The base voltage of the transistor must be high enough to polarize the BE junction and have some voltage on the emitter, and consequently a collector current.
The original circuit is powered at 9V, so that the base voltage is about 0.9V.
To have the same base voltage at 5V, you'd better lower the 100k resostor accordingly.

Consider also that at 5V you must recalculate the 4k7 resistor to maximize the p-p amplitude of the oscillation.

Also consider that the two resistors on the base should have a parallel value of about 10k, so it is better to also rise the 10k. Moreover, the ratio of the collector and the emitter resistors determine the DC gain, and should be mantained abt 10:1