Opening 1NT with Two Doubletons?

It depends on a lot of things. No clear answer. 

Of importance:

1) Quality of the doubletons -- if xx and xx, quite unlikely I'd open 1NT.  If  KQ and KJ doubleton, much more likely to open 1NT.

2) What is the 5-card suit? If a major, usually I wouldn't open 1NT (but see #4).  I would open in the major since I have no rebid problem (can rebid in the 4-card suit next). 

3) What is the 4-card suit?  If 4 spades with a 5-card minor, I'd open one of the minor (easy to bid 1 next). But if 4 hearts with a 5-card minor, 1NT is more tempting (to avoid a potential rebid problem).

4) If exactly 4=5=2=2 in that order, with strong doubletons in the minors and not enough to reverse, I would consider opening 1NT.

updated: March, 2018