Vinyl inflates

Vinyl Inflates permit alkylation with vinyl cations [24, 25] Fluorobenzene reacts with 2 methyl 1-phenyl 1 propenyl triflate to form a diaryl alkene [24J (equation 17)... 

A new synthesis of acetylenes using the reaction ot tnflic anhydride with acyl ylides (equation 48) was developed recently [97] Vinyl inflates, generated in situ, are proposed to be the key intermediates... 

An interesting class ot covalent Inflates are vin l and ar>/ or heteroaryl Inflates Vinyl inflates are used for the direct solvolytic generation of vinyl cations and for the generation of unsaturated carbenes via the a-elimination process [66] A triflate ester of 2-hydroxypyridine can be used as a catalyst for the acylation of aromatic compounds with carboxylic acids [109] (equation 55)... 

For conversion of vinylic Inflates to carboxylic esters and amides, see Cacchi Morcra Ortar Tetrahedron Lett. 1985,26, 1109. 

There are a few exceptions. Certain alkyl and vinylic Inflates alkylate aromatic rings without a catalyst see Gramstad Haszeldinei. Chem. Soc. 1957,4069 Olah Nishimura J. Am. Chem. Soc. 1974,96,2214 Slang Anderson Tetrahedron Lett. 1977, 1485, J. Am. Chem. Soc. 1978,100, 1520. 

For mechanistic investigations on Pd/Ag-catalyzed enyne or arylyne synthesis, Pale et al. mixed various alkynylsilvers with vinyl Inflates or aryl iodides in the presence of palladium salts or complexes (Scheme 10.66).105 This reaction clearly demonstrated that organosilvers can be transmetalated to organopalladium species, even if no halide was present, as demonstrated when starting from vinyl triflates. 

Vinyl Inflates are especially attractive in Stille reactions since they can be prepared regioselectively from enolizable ketones by trapping the enolate oxygen with triflating agents (e.g., Tf20, PhNTf2 ). For reactions of vinyl triflates with... 

Vinyl Inflates.1 These triflates arc generally prepared by reaction of lithium cnolatcs with N-phenyltriflimide, (CFjSC NQHs, 12,395. These new pyridine-based triflimides arc considerably more reactive than N-phenyltriflimidc. 

Carbenes. Primary vinyl inflates also serve as precursors to unsaturated carbenes. Thus isopropylidenecarbene (2) has been generated by treatment of the triflate (1) with potassium r-butoxide at -20°. This unsaturated carbene adds stereospecifically to cis- and fra r-2-butene, an indication that the carbene is a singlet. ... 

SCHEME 3 Z-O-Enecarbamate group as an efficient precursor of Z-vinyl Inflate and its further... 

The use of vinyl inflates in place of halides is attractive due to their easy formation from ketones and the readiness with which they undergo Pd-catalyzed chemistry. A method for the carbonylation of hydroxy alkenyl triflates using Pd(PPh3)4 as catalyst was developed by Crisp and Meyent ii A variety of fused butenolides were synthesized in good to excellent yields using this protocol, as shown in Scheme 9. 

SCHEME 4.277 Use of vinyl Inflates as substrates in the palladium-catalyzed synthesis of vinylphosphines [439, 440]. 

SCHEME 636 Palladium-catalyzed synthesis of vinylboronates from vinyl Inflates [77]. 

SCHEME 7.108 Palladium-catalyzed conversion of vinyl Inflates into vinyl halides [150],... 

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