Tetrafluoroethylene insertion into

A few examples of insertion of activated alkenes into M-Si bonds are known. For example, tetrafluoroethylene inserts into a Mn-Si bond under the influence of UV radiation (equation 73)210. 

Polytetrafluoroethylene, more commonly known as the trademarked brand name Teflon, is formed from the addition polymerization of tetrafluoroethylene. Tetrafluoroethylene, shown in Figure 25.4(c), is an analogue of ethylene in which fluorine atoms have replaced all four of the hydrogen atoms. Teflon is a very good electrical insulator, so it is commonly used to coat wires. It is probably best known, though, as a nonstick substance used to coat bakeware, frying pans, and pots. It is also used in films that can be inserted into threaded joints between metal pipes to make it easier to unscrew the connection when necessary. Because Teflon is chemically inert, it is not possible to cross-link the chains like an elastomer. The structures of some addition polymers, including the structures of their respective monomers and what they are typically used for, are summarized in Table 25.1. 

Tetrafluoroethylene reacts with Fe(CO)3(butadiene) by a two-step oxidative addition process to give (43). The reaction of the rhodium(i) complex Rh(acac)(cod) with hexafluorobut-2-yne results both in trimer-ization of this alkyne, and either its insertion into a y-bonded acetyl-acetonate intermediate or a concerted addition to the acetylacetonate ring, to produce (44), RhCl3,3H20 reacts with 2-methylallyl alcohol, in the presence of 4-methylpyridine (pic), probably via two insertion reactions, to... 

Copyrolysis of 1,1-diehloroperfluoroindane and chlorodifluoromethane or tetrafluoroethylene gives 1-perfluoromethyleneindane as the major product and three minor products [3] (equation 2) Insertion of difluorocatbene into the benzylic carbon-chlorine bond and subsequent loss of a chlonne molecule is observed in the copyrolysis of chlorodifluoromethane and pentafluorobenzotnchlonde to give a-chloroperfluorostyrene as the major product. Aromatic carbon-chlorine bonds are unreactive to the difluorocarbene in this reaction [4] (equation 3). 

A catalytic addition of acidic alcohols or phenols to hexafluoropropene is induced by the complex Pd(PPh3)4 [110]. Catalytic activity is increased in the presence of cocatalytic l,4-bis-(diphenylphosphino)butane (dppb) (Scheme 19). The authors propose a mechanism involving external protonation of a Pd(0)-coordinated olefin and reductive elimination to the ether product, but both steps appear improbable. There is literature precedence for insertion of tetrafluoroethylene into the Pt-O bond of (dppe)PtMe(OMe) to give (dppe)PtMe(CF2CF20Me), but proto-demetallation of the resulting complex has not been reported [111, 112]. 

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