Phosphine sulfides synthesis

P-Chirogenic phosphine/sulfide hybrid phosphine-boranes 80 were synthesized from the reaction between (l )-tosylates 79 [94] and sodium thiolate in DMF at ambient temperature as depicted in Scheme 12, or alternatively by a one pot synthesis consisting of the nucleophilic attack of the chirally induced hthium salt of 74 on phenyl disulfide. Both methodologies provided the desired sul-fide/phosphine boranes in excellent yields [10]. 

The use of other phosphorus-sulfur reagents for heterocyclic synthesis appears rare. It would be interesting to investigate in more detail the reaction of compounds, such as the phosphine sulfides, with organic substrates. Triphenylphosphine sulfide is an effective sulfur transfer agent, as it converts oxiranes into thiiranes in good yield. The reaction proceeds with retention of configuration.128... 

The synthesis uses Evans chemistry to introduce enantioselectively an azide group, which is then reduced to the a-amino group (Scheme 16). Note that in all cases, the phosphinyl group is protected as its sulfide during the synthesis to avoid complication (oxidation) observed with the phosphine. The phosphine sulfide is compatible with Fmoc- and Boc-peptide synthesis conditions. The free phosphine can later be regenerated by treating the sulfide with Raney nickel in MeOH (as shown in Scheme 15) or by methylation followed by treatment with HMPTJ50 This reduction was even applied successfully to sulfide-protected phosphine peptides still attached to the solid support.151 ... 

Tri-n-butyldifluorophosphorane was first obtained upon interaction between tri-re-butylphosphine and hexafluoro-thioacetone dimer.The method described here involves the reaction of tri-n-butylphosphine sulfide with antimony-(III) fluoride. The method is more generally apphcable in the synthesis of difluorophosphoranes from tertiary phosphine sulfides. The only previously reported difluoro-phosphorane, triphenyldifluorophosphorane, was obtained by the reaction of triphenylphosphine or triphenylphos-phine oxide with sulfur(IV) fluoride under autogenous pressure. ... 

The use of the 1-naphthylmethyl moiety as a P—H protecting group in the synthesis of a phosphino macrocycle has been described the protecting group is removed from the phosphine sulfide by treatment with excess potassium naphthalenide (equation 21). ... 

Alternatively, phosphine sulfides and/or phosphine seienides have been screened as active catalysts for phosgene synthesis from CO and Clj [2076]. In one example, a mixture of liquid dichlorine, CCl, and PHjS (0.5%, based on the solvent) was loaded into an autoclave under a CO pressure of about 3 MPa. The reaction, maintained at 10 C for 3 h, resulted in a yield of phosgene of 97%. 

Hexachlorodisilane has been found to be a convenient deoxygenating agent of amine oxides and sulfoxides, and has been used in the synthesis of condensed bridged phosphinesIn addition, the first and only stereospecific desulfurization of phosphine sulfides reported to date was also accom-... 

The triple bond of phosphaalkynes also acts as a dienophile with phosphole sulfides, giving a cycloadduct (167) that readily loses the bridging phosphine sulfide group and is converted to a phosphinine derivative, (168) (Scheme 34) <86ZN(B)93l>. The reaction has practical value as a phosphinine synthesis. 

In principle, the reaction of oxo-Mo(iv) complexes with SAT reagents could produce oxosulfido-Mo(vi) species, especially in the presence of innocent, sterically protective co-ligands. Indeed, this strategy has proved indispensable in the development of scorpionate-based MoHMs (Section 7.4.1.1.3). Related conversions, e.g. of Mo(ii) complexes to sulfido-Mo(iv) species, followed by OAT, may also be useful in the synthesis of oxosulfido-Mo(vi) complexes. Potential sulfur atom donors include elemental sulfur, thiiranes, thiols and phosphine sulfides. However, sulfur s propensity for catenation limits its usefulness in single-atom SAT reactions. To date, thiols and phosphine sulfides have found limited application in such reactions. ... 

Gammon JJ, Gessner VH, Barker GR, Granander J, Whitwood AC, Strohmann C, O Brien P, Kelly B (2010) Synthesis of P-stereogenic compounds via kinetic deprotonation and dynamic thermodynamic resolution of phosphine sulfides opposite sense of induction using (—)-sparteine. J Am Chem Soc 132 13922-13927... 

Gammon JJ, O Brien P, Kelly B (2009) Regioselective lithiation of silyl phosphine sulfides asymmetric synthesis of P-stereogenic compounds. Org Lett 11 5022-5025... 

Li GY (2002) Catalysis using phosphine oxide and phosphine sulfide complexes with Pd and Ni for the synthesis of biaryls and arylamines. Int Patent W02002000574A2, 3 Jan 2002... 

Further work by the same group also applied the deprotonation/electro-philic quenching method for an efficient synthesis of a family of P-stereogenic phosphine/sulfide hybrid ligands (Scheme 5.16). 

Alkylation at Phosphorus. Phosphines and phosphites undergo easy quaternization. Thus methylation of tris(2,6-dimethyl-phenoxy)phosphine with MeOTf, followed by treatment of the product with sodium 2,6-dimethylphenoxide, gave methyltetrakis (2,6-dimethylphenoxy)phosphane. Methoxyphosphonium tri-flates are relatively stable intermediates in Arbuzov reactions Phosphine oxides and sulfides are alkylated. S-Methylation of chiral phosphine sulfides, followed by treatment with hexam-ethylphosphorous triamide, has been advocated as a general synthesis of optically active phosphines. ... 

McCurry and Donovan have employed the ylid adduct for the synthesis of alkylidene lactone 88 in high yields (60-78%). The latter are precursors to 3-alkylfurans 89. Use of the ylid 84 has been reported in the synthesis of lysergic acid and as a catalyst for the preparation of phosphine sulfides. Zweifel and coworkers have studied the triphenylphosphine and... 

SCHEME 4.209 Selective synthesis of unsymmetrical phosphine sulfides [347]. 

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