7 research outputs found
Preparation of Enantiomerically Pure Perfluorobutanesulfinamide and Its Application to the Asymmetric Synthesis of α-Amino Acids.
Asymmetric Synthesis of α‑Branched Amines via Rh(III)-Catalyzed C–H Bond Functionalization
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Asymmetric Synthesis of α‑Branched Amines via Rh(III)-Catalyzed C–H Bond Functionalization
The first asymmetric
intermolecular addition of non-acidic C–H
bonds to imines is reported. The use of the activating <i>N</i>-perfluorobutanesulfinyl imine substituent is essential for achieving
sufficient reactivity and provides outstanding diastereoselectivity
(>98:2 dr). Straightforward removal of the sulfinyl group with
HCl
yields the highly enantiomerically enriched amine hydrochlorides
Asymmetric Synthesis of α‑Branched Amines via Rh(III)-Catalyzed C–H Bond Functionalization
The first asymmetric
intermolecular addition of non-acidic C–H
bonds to imines is reported. The use of the activating <i>N</i>-perfluorobutanesulfinyl imine substituent is essential for achieving
sufficient reactivity and provides outstanding diastereoselectivity
(>98:2 dr). Straightforward removal of the sulfinyl group with
HCl
yields the highly enantiomerically enriched amine hydrochlorides
Preparation of Enantiomerically Pure Perfluorobutanesulfinamide and Its Application to the Asymmetric Synthesis of Amino Acids
Preparation of Enantiomerically Pure Perfluorobutanesulfinamide and Its Application to the Asymmetric Synthesis of α‑Amino Acids
A high
yielding and practical two-step synthesis of enantiomerically
pure perfluorobutanesulfinamide from Senanayake’s 2-aminoindanol-derived
sulfinyl transfer reagent was developed and carried out on a multigram
scale. Straightforward condensation of this sulfinamide with ethyl
glyoxylate provided the <i>N</i>-perfluorobutanesulfinyl
imino ester. The utility of this activated <i>N</i>-sulfinyl
imino ester was demonstrated for reactions that gave either no product
or very low yields with the corresponding less electrophilic <i>N</i>-<i>tert</i>-butanesulfinyl derivative. Specifically,
the RhÂ(III)-catalyzed C–H bond addition of aromatic compounds
to the <i>N</i>-perfluorobutanesulfinyl imino ester provided
arylglycines with very high diastereoselectivities for a range of
directing groups including pyrrolidine amide, azo, sulfoximine, 1-pyrazole,
and 1,2,3-triazole functionalities. Thermal asymmetric aza-Diels–Alder
reactions also proceeded in good yields and with high selectivity,
including for the substituted dienes (<i>E</i>)-1,3-pentadiene
and (2<i>E</i>,4<i>E</i>)-2,4-hexadiene