Synthesis of Highly Enantioenriched Chiral alpha-Aminoorganotins via Diastereoselective Ring Opening of Chiral N-(Arenesulfonyl) 2-Tributylstannyloxazolidines

International audiencetrans-N-(Arenesulfonyl)-2-tributylstannyloxazolidines derived from (R)-phenylglycinol were diaster-ecoselectively ring-opened by soft organometallic reagents in the presence of BF3 center dot OEt2. Both higher order organocuprates and allyltributyltin afforded the desired products in good-to-excellent yields and high diasterecoseloctivities (dr tip to 99/1). The stercochemical assignments of tributylstannyl-beta-aminoalcohols were firmly established from NMR data and after determination of several radiocrystallographic structures. Mechanisms were proposed in order to rationalize the observed selectivities

Iron-Mediated Domino Interrupted Iso-Nazarov/Dearomative (3 + 2)-Cycloaddition of Electrophilic Indoles

International audienceAn efficient domino reaction combining different classes of pericyclic reactions leads to chiral complex polycyclic indoline-based architectures from achiral starting materials under mild conditions. This practical method is based on the ability of iron(III) chloride to promote both 4π electrocyclizations of 2,4-dienals and the C2–C3 umpolung of N-acetylindoles during the dearomative (3 + 2) cycloadditions

Precursors of chiral alpha-amino anions: An improved synthesis of chiral N-(alpha-tributylstannylorgano)oxazolidin-2-ones derived from (R)- or (S)-phenylglycinol

0039-788

In Situ Generation of Cyclopentadienol Intermediates from 2,4-Dienals. Application to the Synthesis of Spirooxindoles via a Domino Polycyclization

International audienceAn efficient domino polycyclization combining different classes of pericyclic reactions leads to complex spiroxindoles under mild conditions. This domino process represents a rare example of an in situ formation of cyclopentadienol derivatives from an interrupted iso-Nazarov electrocyclization of 2,4-dienals and their use in [4 + 2] cycloaddition reactions. According to the reaction conditions, different polycyclic architectures are obtained in good yields and excellent diastereoselectivities

Chiral a-Aminoorganostannanes : Precursors of a-Aminoorganolithiums

Communication par affiche intitulée (présentée par V. Coeffard) : Chiral a-Aminoorganostannanes : Precursors of a-Aminoorganolithium