Hydrogen bonds around M(mu-O)2M rhombs: stabilizing a {CoIII(mu-O)2CoIII} complex at room temperature.

Experimental Section General procedure for synthesis of thiazolines: Trifluoromethanesulfonic anhydride (50 mL, 0.3 mmol) was added slowly to a solution of triphenylphosphane oxide (167 mg, 0.6 mmol) in dry CH2Cl2 (2 mL) at 0 8C. The reaction mixture was stirred for 10 min at 0 8C and then adjusted to the desired reaction temperature, followed by addition of the fully protected cysteine N-amide (0.2 mmol). The reaction progress was monitored by TLC. The reaction mixture was quenched with 10% aqueous NaHCO3 solution. The aqueous layer was extracted with CH2Cl2, and the combined organic layers were dried over Na2SO4, filtered, and concentrated. The resultant crude product was purified by flash chromatography with EtOAc/hexanes. More details and characterization data of the products can be found in the Supporting Information.