Pseudoephedrine-based chiral silane

Inspired by the previous results, Leighton et al. reported the enantioselective [3 + 2] acylhydrazone-enol ether cycloaddition reaction by employing the same pseudoephedrine-based chiral silane. The pyrazohdine product was obtained in 61% yield with 6 1 dr and 77% ee in 24 h. The use of tert-butyl vinyl ether led to an improvement in both diastereoselectivity and enantioselectivity as shown in Scheme 34 [108]. 

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