Iodonitrene in Action: Direct Transformation of Amino Acids into Terminal Diazirines and N-Diazirines and Their Application as Hyperpolarized Markers.

A one-pot metal-free conversion of unprotected amino acids to terminal diazirines has been developed using phenyliodonium diacetate (PIDA) and ammonia. This PIDA-mediated transformation occurs three consecutive reactions and involves an iodonitrene intermediate. This method is tolerant to most functional groups found on the lateral chain of amino acids, it is operationally simple, and it can be scaled up to provide multigram quantities of diazirine.

α-Trifluoromethylated tertiary homoallylic amines: diastereoselective synthesis and conversion into β-aminoesters, γ- and δ-aminoalcohols, azetidines and pyrrolidines.

The diastereoselective addition of allyl zinc and allylindium derivatives to α-trifluoromethyl N-tert-butanesulfinyl hemiaminals, bench stable precursors of aryl and alkyl trifluoromethyl ketimines, allows the synthesis of homoallylic amines containing a tetrasubstituted carbon stereocentre bearing a trifluoromethyl group with good diastereoselectivities (up to dr > 99 : 1). This approach was also suitable for accessing chiral homoallylic amines bearing two contiguous stereocenters. The synthetic usefulness of N-tert-butanesulfinyl homoallylamines was illustrated by preparing various trifluoromethylated nitrogen containing bifunctional synthons (aminoesters, aminoalcohols) and small azaheterocycles (azetidines, pyrrolidines).