Nonaflate

On the contrary, tnfluoromethyl groups severely impede Sj l or reactions when located a to the reaction site. However, aminolysis of l-phenyl-2,2,2,-tri-fluoroethyl tosylate [Sd] and tnfluoroethyl chloride [ST] and its corresponding nonaflate [SS] can be performed under severe conditions (equation 76). 

The 6 -phosphines dppe, dppp, and dppb were also effective for this coupling. Entry 3 is an example of use of a vinyl triflate. Entries 4 and 5 illustrate the use of perfluorobu-tanesulfonate (nonaflate) as an alternative leaving group to triflate. The organozinc... 

In addition to bromides and iodides, the reaction has been successfully extended to chlorides,163 triflates,164 and nonafluorobutanesulfonates (nonaflates).165 These reaction conditions permit substitution in both electron-poor and electron-rich aryl systems by a variety of nitrogen nucleophiles, including alkyl or aryl amines and heterocycles. These reactions proceed via a catalytic cycle involving Pd(0) and Pd(II) intermediates. 

Nonaflates obtained from enolates of 1,3-diketones and /3-ketoesters serve as easily available coupling partners (93).321... 

The indium nonaflate (In(ONf)3)-catalyzed annulation of 2-thienyl- and 2-furylindoles, bithiophenes, and bifurans with methyl propargyl ether also provides tetracyclic heteroaryl annulated [ ]carbazoles in moderate to good yields <2005AGE1336> (Equation (104) Table 10). 

To our delight we found that palladium-catalyzed cross-couplings between sulfoximines and aryl halides (or aryl nonaflates) work very well, affording N-arylated products in high yield [45]. Generally, Buchwald s Pd(OAc)2/BlNAP catalyst system (with CS2CO3 and toluene at 100 °C) was applied, and thereby a variety of N-aryl sulfoximines 58 - including enantiopure ones - were prepared (Scheme 2.1.1.17). 

For reviews of triflates. nonaflates. and other fluorinated ester leaving groups, sec Stang I lanack Subramanian Synthesis 1982, 85-126 Howells Me Cown Chem. Rev. 1977, 77, 69-92, pp. 85-87 wCrossland Wells Shiner J. Am. Chem. Soc. 1971, 93, 4217. 

As another alternative to triflates, aryl nonaflates (ONf) are easily prepared from phenol and commerically available perfluorobutane sulfonyl fluoride 243, and used for Pd-catalysed coupling with halides [111]. Aryl nonaflates are more reactive than aryl triflates. / -Iodophcnyl nonaflate (244) gives 245 by chemoselective reaction of the... 

One of the key steps in this synthesis is the domino-ZZeck reaction forming 45.19 The Pd-catalyzed coupling of alkenes with vinyl- and aryliodides was discovered in 1968 by R. F. Heck nowadays also triflates or nonaflates are used as substrates.20... 

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