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Direct nucleophilic trifluoromethylation of carbonyl compounds by potent greenhouse gas, fluoroform: Improving the reactivity of anionoid trifluoromethyl species in glymes.

ABSTRACT: A simple protocol to overcome the problematic trifluoromethylation of carbonyl compounds by the potent greenhouse gas "HFC-23, fluoroform" with a potassium base is described. Simply the use of glymes as a solvent or an additive dramatically improves the yields of this transformation. Experimental results and DFT calculations suggest that the beneficial effect deals with glyme coordination to the K⁺ to produce [K(polyether)_n]⁺ whose diminished Lewis acidity renders the reactive anionoid CF₃ counterion species more 'naked', thereby slowing down its undesirable decomposition to CF₂ and F^- and simultaneously increasing its reactivity towards the organic substrate.

SUBMITTER: Saito T

PROVIDER: S-EPMC6068191 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature

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Direct nucleophilic trifluoromethylation of carbonyl compounds by potent greenhouse gas, fluoroform: Improving the reactivity of anionoid trifluoromethyl species in glymes.

Saito Takuya T Wang Jiandong J Tokunaga Etsuko E Tsuzuki Seiji S Shibata Norio N

Scientific reports 20180731 1

A simple protocol to overcome the problematic trifluoromethylation of carbonyl compounds by the potent greenhouse gas "HFC-23, fluoroform" with a potassium base is described. Simply the use of glymes as a solvent or an additive dramatically improves the yields of this transformation. Experimental results and DFT calculations suggest that the beneficial effect deals with glyme coordination to the K+ to produce [K(polyether)n]+ whose diminished Lewis acidity render ...[more]

PMID: 30065282

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