Formation and reactivity of aliphatic N-sulfinylamines

Aliphatic N-sulfinylamines were prepared by two methods, direct sulfinylation with thionyl chloride and trans-sulfinylation. The latter process involves the transfer of a sulfinyl group from a less basic N-sulfinylsulfonamide nitrogen to a more basic amine nitrogen. Benzylamine, which upon treatment with thionyl chloride yields only benzaldehyde, could not be trans-sulfinylated. A mechanistic rationale for the failure to isolate benzyl- N-sulfinylamine which calls for rearrangement of the unstable N-sulfinylamine through a four-membered transition state, has been proposed.

The reactivity of various aliphatic N-sulfinylamines in strong base solution was explored. Although the expectation was that a resonance stablized carbanion under nitrogen would result from deprotonation of the N-sulfinylamines, no experimental verification of this was found.

It is proposed here that electron density in deprotonated N-sulfinylamine resides primarily on oxygen. The reactivity of aliphatic N-sulfinylamines appeared to be most clearly defined by the dominance of the oxygen based anion.