Diastereomers (R_C,S_P)- and (R_C,R_P)-S-methylP-(3-azidopropyl)-N-[(1R)-1-phenylethyl]phosphonamidothioate

Abstract

Diastereoisomers of the title organophosphorus compound, C12H19N4OPS, denoted RCSP, (I), and RCRP, (II), were structurally characterized and compared. Asymmetric phosphorus compounds are of interest with regard to the use of these systems as possible protein probes via the stereoselective delivery of an azide group tethered to the P atom into key protein regions. The diastereomers were produced in a 1:1 mixture and isolated by chromatography. Although both isomers crystallize in the same space group with superficially similar cell constants, conformational and packing differences are pronounced. Despite the conformational differences, strong intermolecular hydrogen bonding links both isomers into chains parallel to the a axis [N...O = 2.8609 (18) and 2.966 (3) Å in (I) and (II), respectively], with C—H...π interchain interactions of ca 3.5 Å.

Phenylazo-BODIPYs: Direct Access via Pd-Catalysis

“…Another plausible mechanism might be a β-hydride elimination in the final step of the catalytic cycle whereby the coupled hydrazo intermediate is again involved (Scheme 3). In contrast to previous Pd-catalyzed reactions with phenylhydrazine, 10 use of (±)-BINAP as bidentate ligand might allow this alternative pathway. 20 .…”

“…Crystallographic data for the structures reported here have been deposited with the Cambridge Crystallographic Data Centre. 10 CCDC 2277682 (3ab), 2282387 (3ac), and 2284383 (3ae) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures.…”

“…However, there are only few reports of Pd-catalyzed reactions with hydrazines to directly insert two adjacent nitrogen atoms. 10 To the best of our knowledge, none of these report the formation of an azo group. Nonetheless, in situ formation of an azo group can occur when using DMSO as solvent.…”