1,3-phosphorus zwitterions with cyano-group at anion center

Abstract

This review focuses on synthesis and properties of 1,3-phosphorus-containing zwitterions that have at the anionic center cyano-group and either ester (type one) or carbamate (type two) moieties. Zwitterions belonging to type one possess dual nucleophile reactivity, i.e., depending on the properties of the electrophiles they may form either C-or N-derivatives. Zwitterions belonging to type two possess triple nucleophile reactivity. In their reactions with electrophiles, they may form even three types of derivatives, i.e., at the C-, O-or Natoms. This nucleophile multiplicity is not just interesting from the theoretical standpoint but may also open the ways to the synthesis of new compounds that can be important from the practical standpoint, such as physiologically active compounds, catalysts, analytical reagents, etc.

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

“…In case of methyl methacrylate, the reaction is accompanied by oligomerization of the Michael acceptor (Supporting Information File 1, Figure S47). A similar oligomerization reaction has been reported for cyanoacrylates [40]. Apart from the adducts of these two very weak Michael acceptors, the zwitterionic species 2a-i described herein are quite stable.…”

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

“…S47). A similar oligomerization reaction has been reported for cyanoacrylates [39]. Apart from the adducts of these two very weak Michael acceptors, the zwitterionic species 2a-2i described herein are quite stable.…”