Reaction of quadricyclane with fluorinated sulfur-containing compounds

2,2,4,4-Tetrakis(trifluoromethyl)-1,3-dithietane (1) reacts with quadricyclane (2) without a catalyst at ambient or elevated temperature, giving the corresponding cycloadduct, 3-thia-4,4-bis(trifluoromethyl)tricyclo[5.2.1.0(2,5)]non-7-ene (3) in 74% yield. Similar reaction of 2,2,4,4-tetrafluoro-1,3-dithietane (4) at elevated temperature results in the formation of 3-thia-4,4-difuorotricyclo[5.2. 1.0(2.5)]non-7-ene (5a) along with two other byproducts. Both (n-C4F9S)(2) and [(CF3)(2)CFS](2) react with 2 upon heating (90-100 degrees C) giving the corresponding nortricyclanes 9a,b and 11a,b in high yield. The reactions of CH3SO2Cl or CF3SO2Cl and 2 proceed at ambient temperature leading to mixture of isomeric nortricyclanes 13a,b and 15a,b. Reactions of quadricyclane reported here are apparently initiated by a single-electron transfer from quadricyclane to neutral substrates, the first such observed for an alkane. (c) 2005 Elsevier B.V. All rights reserved.