A while ago, I provided an answer to a question on Biology.SE concerning the half-life of dNTPs under PCR conditions. At the beginning of my answer, I give a qualification:
Caveat: ignoring the bonds between the different parts of dNTPs likely misrepresents the stability of the intact molecule, given that the covalent bonds between the nucleobase, sugar, and phosphate pieces each have their own relative stabilities.
How wrong is my approach to model the stability of the whole dNTP by the stability of its pieces? To what extent do the covalent bonds between the constituent molecules (indicated with red arrows below) contribute to the thermal stability of the dNTP as a whole? What is the organic chemistry explanation (resonance?) for why the intact molecule would be more (or less) stable than its least stable constituent in a neutral-buffered aqueous solution at 95 °C?
Edit, re: Karsten Theis's comment
You don't suggest a mechanism of degradation, or a degradation product.
Per the linked Biology.SE question, I'm interested in any degradation mechanism that would lead to the dNTP being no longer be polymerizable by DNA polymerase. As I understand it, the incoming dNTP base-pairs (hydrogen bonds) with the template, allowing the ribose 3' hydroxyl group to attack the triphosphate group on the incoming nucleotide, yielding a phosphodiester bond and a pyrophosphate leaving group.
So, any mechanism that results in a product that (1) interferes with hydrogen bonding associations of the dNTP with its template or (2) prevents subsequent phosphodiester bond formation is fair game. Even though deamination of dCTP may inhibit specific polymerases, my understanding is that dUTP can still be incorporated by the polymerases used in PCR, so that specific reaction is not within the scope of my question.