Asymmetric reduction of ketimines with trichlorosilane employing an imidazole derived organocatalyst.
نویسندگان
چکیده
Organocatalysts for the asymmetric reduction of ketimines are presented that function well at low catalyst loadings providing chiral amines in good yield and enantioselectivity, the latter appearing to be independent of the ketimine substrate geometry.
منابع مشابه
L-Valine derived chiral N-sulfinamides as effective organocatalysts for the asymmetric hydrosilylation of N-alkyl and N-aryl protected ketimines.
L-Valine derived N-sulfinamides have been developed as efficient enantioselective Lewis basic organocatalysts for the asymmetric reduction of N-aryl and N-alkyl ketimines with trichlorosilane. Catalyst 3c afforded up to 99% yield and 96% ee in the reduction of N-alkyl ketimines and up to 98% yield and 98% ee in the reduction of N-aryl ketimines.
متن کاملDendron-anchored organocatalysts: the asymmetric reduction of imines with trichlorosilane, catalysed by an amino acid-derived formamide appended to a dendron.
Asymmetric reduction of ketimines with trichlorosilane can be catalysed by the Lewis-basic N-methylvaline-derived formamide anchored to a soluble dendron () with good enantioselectivity (</=94% ee) and low catalyst loading (typically 5 mol%) at room temperature in toluene. This protocol represents an improvement and simplification of the isolation procedure and recovery of the catalyst.
متن کاملEvolution of chiral Lewis basic N-formamide as highly effective organocatalyst for asymmetric reduction of both ketones and ketimines with an unprecedented substrate scope.
L-Pipecolinic acid derived Lewis basic N-formamide has been developed as a first highly effective catalyst for the asymmetric reduction of aromatic and aliphatic ketones as well as aromatic and aliphatic ketimines in good to high enantioselectivity.
متن کاملCatalyst development for organocatalytic hydrosilylation of aromatic ketones and ketimines.
A new family of Lewis basic 2-pyridyl oxazolines have been developed, which can act as efficient organocatalysts for the enantioselective reduction of prochiral aromatic ketones and ketimines with trichlorosilane, a readily available and inexpensive reagent. 1-Isoquinolyl oxazoline, derived from mandelic acid, was identified as the most efficient catalyst of the series, capable of delivering hi...
متن کاملA highly enantioselective lewis basic organocatalyst for reduction of N-aryl imines with unprecedented substrate spectrum.
L-Pipecolinic acid derived formamides have been developed as highly efficient and enantioselective Lewis basic organocatalysts for the reduction of N-aryl imines with trichlorosilane. Catalyst 4b afforded high isolated yields (up to 98%) and enantioselectivities (up to 96%) under mild conditions with an unprecedented substrate spectrum.
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ورودعنوان ژورنال:
- Organic & biomolecular chemistry
دوره 7 2 شماره
صفحات -
تاریخ انتشار 2009