Triflates leaving group

Fig. 34 Approach to higher carbon sugars via the Wittig-type reaction Unusual rearrangement of the enone induced by triflate leaving group. 

Carbocations with trivalent carbon may have carbon with coordination number 2. Acyl ions have already been mentioned the vinyl cations, or car-bynium ions (26), have been detected as intermediates in addition of electrophiles to acetylenes and allenes and in solvolysis reactions with the highly reactive trifluoromethanesulfonate (triflate) leaving group.84 Vinyl cations are expected... 

Halide and triflate leaving groups are also involved with palladium catalysis in the most general of all these reactions with vinyl electrophiles. These use a main group rather than transition metal, chiefly boron or tin, in stoichiometric amounts to mark one molecule as nucleophilic and then... 

Tosylates, Mesylates, and Triflates Leaving Group Derivatives of Alcohols 514... 

TOSYLATES, MESYLATES, AND TRIFLATES LEAVING GROUP DERIVATIVES OF ALGOHOLS... 

C-C bond formation via transition-metal-catalysed cross coupling of -activated enols has been reviewed (97 references) while less reactive than systems involving halide or triflate leaving groups, vinyl phosphates have significant advantages in terms of cost, stability, and low toxicity... 

Naturally, further use has been made of the triflate leaving group, O SOj CFs = OTf, in mechanistic studies, including work on inter-... 

The triflate leaving group was introduced to coupling reactions as an alterative to halogens. They are particularly useful when there is no simple way to prepare the required halide partner. Aryl triflates can be prepared from phenols and pyridyl triflates can be prepared from pyridones. This transformation is usually achieved using triflic anhydride and an amine base. The coupling of a triflate 2.191, derived from quinolone 2.190, with stannane 2.192 was used in a short synthesis of dubamine 2.193 (Scheme 2.66). 

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