Sterically Hindered Arene Chalcogenols

SUBMITTED BY MANFRED BOCHMANN and KEVIN J. WEBB CHECKED BY M. A. MAILKf, J. R. WALSH,1 and P. O BRIEN1 

1 Department of Chemistry, Queen Mary and Westfield College, University of London, London El 4NS, UK. 

Unless otherwise stated, all operations are carried out in flame-dried glassware under an inert gas atmosphere using standard Schlenk techniques.4 Solvents were dried over sodium (light petroleum, bp 40-60°C) or sodium-benzophenone (diethyl ether, THF). Lithium triethylhydroborate (1 — ) and hydrogen tetrafluoroborate (1 — ) diethyl ether complex were obtained from Aldrich and used as supplied. 

Ar2Se2 + 2LiBHEt3 - 2Ar SeLi + 2BEt3 + H2 Ar SeLi + HBF4Et20 - Ar SeH + LiBF4 Ar = 2,4,6-f-Bu3C6H2 

In contrast to Ar SH, Ar SeH is air-sensitive and must be handled and stored under inert gas. Air oxidation or treatment with oxidizing agents such 

2 mmol). The color changes from deep red to green. After stirring for another 15 min the solvent is removed in vacuo and the solid residue suspended in light petroleum (60 mL), stirred, and cooled to — 78°C. Hydrogen tetrafluoroborate(l —) diethyl ether complex (85% solution, 1 g, 

---

Polymer formation is still observed with some sterically hindered thiolates, 2,4,6-Ao-propyl thiophenolate, and 2,4,6-trimethyl thiophenolate complexes have been studied. They can be synthesized by the reaction of Zn[N(SiMe3)2]2 with the appropriate arene chalcogenol. With the least steric bulk, the trimethyl derivative forms coordination polymers that can only be dissolved in strongly coordinating solvents. The iso-propyl derivative is more soluble forming oligomers in solution. 1... 

---