@article{c5b62efe33f34de0beac4c31c71c54b5,
title = "Preparation and characterization of sterically protected primary phosphine sulfide and oxide",
abstract = "Sterically protected primary phosphine sulfide (1) and oxide (3), were prepared from 2,4,6-tri-tert-butylphenylphosphine (2) and were characterized as stable compounds.",
author = "Masaaki Yoshifuji and Katsuhiro Shibayama and Kozo Toyota and Naoki Inamoto",
note = "Funding Information: 309 (M+-H , 75%), 277 (ArylPH+, 100%); high resolution for CIBHBIPS 310.1883. The oxidation of primary phosphines is quite difficult to control and such compounds at the first oxidation stage even if generated have poor thermal stability.6y7 Since the steric protection by the 2,4,6-tri-tert-butylphenyl group in the sulfide (1) proved effective, an attempt to isolate the correspondingp hos-phine oxide was made as follows. The phosphine (2) N was allowed to react with equimolar amount of aqueous ethanolic hydrogen peroxide at room temperature to give the primary phosphine oxide (3 almost quantitatively. Mp 172 - 172.5'C (from EtOH - EtzO); 31P NMR (CDC13) -10.0 ppm (t, 'JpH= 490.7 Hz); 31P{1H} NMR appeared as a quintet on adding D20 (ArylP(O)Dz, 'JpD= 73.9 Hz); 'H NMR (CDC13) 7.85 (2H, d, 'JpH= 481.6 Hz, PHz), - 7.49 (2H, d, 'JpH= 4.2 Hz, arom.), 1.62(18H, s, o-But), 1.32 (9H, s, p-But); 13C{'H) NMR (CDC13) 156.8 (d, o-arom., 2J CP = 8.3 Hz), 154.3 (d, p-arom., 'Jcp= 2.9 Hz), 124.9 (d, ipso-arom., 'Jcp= 95.2 HZ), 38.6 (d, o-C(CH,)3, 3Jcp= 3.9 Hz), 35.2 (P-C(CH,)~), -33.9 (o-C(CH3)3),31.0 (p-C(CH313); IR (KBr) vPH 2440 cm-' and vpo 1172 cm{\textquoteleft} '; MS m/e 294 (Mf, 14%), 57 (Bu+, 100%). The oxide (3 was very stable for a long period of time at room temperatureeven in the solid state probably due to the steric protection from the intermolecular oxidation-reduction and from aerial oxidation, in contrast to octylphosphine oxide, which liquified within 1 h at room temperature in the solid state,6 reported by Buckler and Epstein. The very stable primary phosphine sulfide (3 and oxide (3 thus obtained' might serve as good model compounds for the study of the P=S and P=O species. Further studies on the reaction of such compounds are in progress. This work was supported in part by Science Research Grant-in-Aid (543008 and 57540276) from the Ministry of Education, Science and Culture of Japan.",
year = "1983",
doi = "10.1016/S0040-4039(00)88307-0",
language = "English",
volume = "24",
pages = "4227--4228",
journal = "Tetrahedron Letters",
issn = "0040-4039",
publisher = "Elsevier Ltd.",
number = "39",
}