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Phosphazenyl Phosphines: The Most Electron‐Rich Uncharged Phosphorus Brønsted and Lewis Bases
Author(s) -
Ullrich Sebastian,
Kovačević Borislav,
Xie Xiulan,
Sundermeyer Jörg
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201903342
Subject(s) - phosphazene , chemistry , phosphorus , lewis acids and bases , proton affinity , affinities , transition metal , metal , stereochemistry , medicinal chemistry , computational chemistry , crystallography , inorganic chemistry , organic chemistry , ion , catalysis , polymer , protonation
Abstract It was discovered that phosphazenyl phosphines (PAPs) can be stronger P‐superbases than the corresponding Schwesinger type phosphazene N‐superbases. A simple synthetic access to this class of PR 3 derivatives including their homologization is described. XRD structures, proton affinities (PA), and gas‐phase basicities (GB) as well as calculated and experimental p KBH+values in THF are presented. In contrast to their N‐basic counterparts, PAPs are also privileged ligands in transition metal chemistry. In fact, they are currently the strongest uncharged P‐donors known, exceeding classical and more recently discovered ligands such as PtBu 3 and imidazolin‐2‐ylidenaminophosphines (IAPs) with respect to their low Tolman electronic parameters (TEPs) and large cone angles.