Ruthenium(II) porphyrin catalyzed cyclopropanation of alkenes with tosylhydrazones

The diastereoselective ruthenium(II) porphyrin catalyzed cyclopropanation of a variety of alkenes with aryl diazomethanes generated in situ from stable tosylhydrazone derivatives, was achieved in good to excellent yields (up to 92%) and product turnovers. The practical utility of [Ru-II(p-Cl-TPP)(CO)] (H-2(p-Cl-TPP) = meso-tetrakis(p-chlorophenyl)porphyrin) 3 was illustrated in the synthesis of the potent HIV-1 reverse transcriptase inhibitor 10. Preferential formation of sulfone products for reactions involving o- and m-monosubstituted aryl tosylhydrazones demonstrated a hitherto unknown ruthenium(11) porphyrin catalyzed sulfonation reaction. (C) 2003 Elsevier Ltd. All rights reserved.