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Updated: Feb 18, 2026

Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy
Published on: February 20, 2020
An Intramolecular Lewis Adduct with Diverse FLP Reactivity
Hui Li1, Shaoying Ju1, Ting Chen1
1Institute of Drug Discovery Technology and Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, Zhejiang, China.
Abstract:
A stable intramolecular Lewis adduct 1 was prepared by hydroboration of 2-diphenylphosphinobenzaldehyde with HB(C6F5)2. Despite its intramolecular Lewis pairing, 1 exhibits pronounced frustrated Lewis pair-type reactivity toward aldehydes, alkynes, azides, and isocyanides, enabling diverse transformations. Isolated products include aldehyde 1,2-addition derivatives (2-4), head-to-tail dimerized alkyne adducts (5 and 6), Staudinger-type phosphinimine (7), Lewis adducts of isocyanides (8 and 9), and the [4 + 2] cycloaddition product (10) from 2-isocyanonaphthalene. All compounds were fully characterized, and the reaction mechanism is also considered.
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