Publications by authors named "Siobhan R Smith"
Article Synopsis
- A highly selective Lewis base-catalyzed reaction is introduced, allowing for the efficient synthesis of oxazolidin-4-ones through a [3+2] cycloaddition involving ammonium enolates and oxaziridines.
- The use of enantioenriched oxaziridine creates a matched/mismatched effect with the catalyst, enabling the production of either syn- or anti-stereodefined compounds with high selectivity and yield.
- The resulting oxazolidin-4-one products can be further modified into valuable functionalized building blocks in organic synthesis.
Isothiourea HBTM-2.1 catalyses the Michael addition-lactonisation of 2-aryl and 2-alkenylacetic acids and α,β-unsaturated trichloromethyl ketones. Ring-opening of the resulting dihydropyranones and subsequent alcoholysis of the CCl3 ketone with an excess of methanol gives a range of diesters in high diastereo- and enantioselectivity (up to 95 : 5 dr and >99% ee).
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- Isothiourea HBTM-2.1 is a catalyst used for an asymmetric chemical reaction involving Michael addition and lactonization.
- This reaction utilizes aryl- and alkenylacetic acids alongside α-keto-β,γ-unsaturated phosphonates, which act as substitutes for α,β-unsaturated esters.
- The process results in the formation of a variety of stereodefined lactones or enantioenriched functionalized diesters when the lactone ring is opened.
The isothiourea HBTM-2.1 (5 mol %) catalyzes the asymmetric formal [2 + 2] cycloaddition of both arylacetic acids (following activation with tosyl chloride) and preformed 2-arylacetic anhydrides with N-sulfonylaldimines, generating stereodefined 2,3-diaryl-β-amino esters (after ring-opening) and 3,4-diaryl-anti-β-lactams, respectively, with high diastereocontrol (up to >95:5 dr) and good to excellent enantiocontrol. Deprotection of the N-tosyl substituent within the β-lactam framework was possible without racemization by treatment with SmI2.
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