CATALYTIC MACROCYCLIZATION OF 3,3-DIMETHYLTHIETANE BY RE-2(CO)(9)(SCH2CME2CH2)

The reaction of Re-2(CO)(9)(NCMe), 1, with 3,3-dimethylthietane (SCH2C Me2CH2, 3,3-DMT) yielded the complex Re-2(CO)(9)(SCH2CMe2CH2), 2. Comp ound 2 has been found to react with 3,3-DMT at 100 degrees C to yield the polythioether macrocycles 3,7,7,11,11-hexamethyl-1,5,9-trithiacycl ododecane, 3 (Me(6)12S3), ,15-octamethyl-1,5,9,13-tetrathiacyclo-hexad ecane, 4 (Me(8)16S4), and 19-decamethyl-1,5,9,13,17-pentathia-cycloeic osane, 5 (Me(10)20S5), catalytically, but the activity and yields of t he macrocycles are low. High molecular weight oligomers of 3,3-DMT are the principal products. A macrocyclization mechanism consisting of a metal-induced ring-opening cyclooligomerization of three, four, and fi ve molecules of 3,3-DMT, respectively, is proposed. The reaction of 3 with CpMn(CO)3 in the presence of UV irradiation yielded the complex C pMn(CO)(2)(eta(1)-Me(6)12S3), 6. The molecular structures of each of t he macrocycles 3, 4, and 5 and the complexes 2 and 6 were determined b y single-crystal X-ray diffraction analyses.