Construction of adjacent spiro-quaternary and tertiary stereocenters through phosphine-catalyzed asymmetric [3+2] annulation of allenoates with alkylidene azlactones.
نویسندگان
چکیده
A novel axially chiral spiro-phosphine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of alkylidene azlactones with various allenic esters has been developed, affording the corresponding functionalized spirocyclic products in moderate to excellent yields under mild conditions. These spirocyclic products as masked amino acids can be easily transformed into aspartic amino acid analogues.
منابع مشابه
Phosphine-catalyzed [3+2] annulation of α-substituted allenoates with ester-activated α,β-unsaturated imines: a novel variation of the Lu [3+2] cycloaddition reaction.
A phosphine-catalyzed [3+2] annulation reaction of α-substituted allenoates with ester-activated α,β-unsaturated imines is reported, which provides new and efficient access to highly functionalized cyclopentenes bearing one all-carbon quaternary center. This reaction also expands the scope of the famous Lu [3+2] cycloaddition reaction.
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عنوان ژورنال:
- Chemical communications
دوره 48 22 شماره
صفحات -
تاریخ انتشار 2012