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Publication - Dr Adam Noble

    Ring-Opening Lithiation-Borylation of 2-Trifluoromethyl Oxirane: A Route to Versatile Tertiary Trifluoromethyl Boronic Esters

    Citation

    Nandakumar, M, Rubial, B, Noble, A, Myers, EL & Aggarwal, VK, 2019, ‘Ring-Opening Lithiation-Borylation of 2-Trifluoromethyl Oxirane: A Route to Versatile Tertiary Trifluoromethyl Boronic Esters’. Angewandte Chemie - International Edition.

    Abstract

    Stereogenic trifluoromethyl‐substituted carbon centres are highly sought‐after moieties in pharmaceutical and agrochemical discovery. Here, we show that lithiation–borylation reactions of 2‐trifluoromethyl oxirane give densely functionalised and highly versatile trifluoromethyl‐substituted α‐tertiary boronic esters. The intermediate boronate complexes undergo the desired 1,2‐rearrangement of the carbon‐based group with complete retentive stereospecificity, a process that was only observed in non‐polar solvents in the presence of TESOTf. Although the trifluoromethyl group adversely affects subsequent transformations of the α‐boryl group, Zweifel olefinations provide trifluoromethyl‐bearing quaternary stereocenters substituted with alkenes, alkynes and ketones.

    Full details in the University publications repository