Why does N(OH)3 not exist? The hydrolysis of Group-15 tetrahalides gives us their hydroxides via a $\ce{S_{N^2}}$ mechanism:
$$\ce{PCl3 + 3H2O -&gt; H3PO3 + 3HCl}$$
Nitrogen Trichloride, however, yields a different set of products, not forming the trihydroxide as expected.
$$\ce{NCl3 + 3H2O -&gt; NH3 + 3HOCl}$$

A little bit of research led me to this exact same question (with 2 unsatisfactory answers) and this article, which claims that it exists, but I cannot read it. Why does $\ce{N(OH)3}$ not exist?

Another thought along similar lines is the existence of gem-diols in general, which are quite unstable, as well as $\ce{C(OH)4}$, which does not seem to exist as well. Is this an abnormal property of period 2 elements? All the other elements in group 14 and 15 form stable hydroxides whereas the first members do not seem to do so.
Although the acid and its salts are unknown, orthonitrite esters have been found, and from a natural source at that [1].  The orthonitrite function, which is trivalent rather than monovalent as nitrate would be, is incorporated into a macrocycle that hinders its decomposition.

The picture below is from Ref. 1.

Reference:

1.
Leanne Murray,* Tang K. Lim,* Graeme CurrieB and Robert J., "Aplidites (A-G): Macrocyclic Orthonitrites from 
an Australian Tunicate, Aplidium sp.", Aust. J. Chem., 1995, 48, 1253-1266.Link