A new concept for selectivity control in carbocation driven reactions has been identified, which allows for the chemo‐, regio‐ and stereoselective addition of nucleophiles to alkynes: Assisted Vinyl Cation Formation, enabled by a Li+‐based supramolecular framework. Mechanistic analysis of a model complex (Li2NTf2+ · 3 H2O) confirms, that solely the formation of a complex of the transition state of the alkyne protonation with the incoming nucleophile is responsible for the resulting selective N‐addition to the vinyl cation. Into the bargain, a general synthetic procedure to previously inaccessible vinyl triflimides is provided, via an operationally simple protocol.
from A via a.sfakia on Inoreader http://bit.ly/2WsiRWZ
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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,