5-Mercaptotetrazolyl-derived metallaboratranes

Abstract

The reactions of 1-tert butyl-5-thiotetrazole (Htt^tBu) with Na[BH₄] provides Na[H₂B(tt^tBu)₂] (Na[1]) or Na[HB(tt^tBu)₃] (Na[2]) in refluxing THF or xylene, respectively. Treating [RuCl(Ph)(CO)(PPh₃)₂] with Na[2] affords the triply-buttressed ruthenaboratrane [Ru(CO)(PPh₃){κ⁴-B,S,S′,S′′-B(tt^tBu)₃}] (5) whilst Na[1] with [IrCl(CO)(PPh₃)₂] or [RuCl(Ph)(CO)(PPh₃)₂] provides rare examples of doubly-buttressed metallaboratranes [IrH(CO)(PPh₃){κ³-B,S,S′-BH(tt^tBu)₂}] (7) and [Ru(CO)(PPh₃)₂{κ³-B,S,S′-BH(tt^tBu)₂}] (12), the latter via the isolable thiotetrazoylborate complex [Ru(Ph)(CO)(PPh₃){κ³-H,S,S′-H₂B(tt^tBu)₂}] (11).