Stereospecific Synthesis of -2,5-Disubstituted Pyrrolidines via ,-Acetals Formed by Hydroamination Cyclization-Hydroalkoxylation of Homopropargylic Sulfonamides in HFIP.

We reported a novel two-step stereoselective synthesis of functionalized pyrrolidines from homopropargylic sulfonamides and nucleophiles via an isolable ,-acetal intermediates. This reaction features mild conditions and good scope of substrates. In addition, the use of hexafluoroisopropanol, acting as a solvent, an additive, a weak nucleophile, and a good leaving group, is pivotal to the success of the method.

Correction: Materials with low dielectric constant and loss and good thermal properties prepared by introducing perfluorononenyl pendant groups onto poly(ether ether ketone).

[This corrects the article DOI: 10.1039/C7RA13600E.].

Materials with low dielectric constant and loss and good thermal properties prepared by introducing perfluorononenyl pendant groups onto poly(ether ether ketone).

A new monomer, 2,6-difluorophenyl-(4'-perfluorononenyloxy)phenyl-methanone (2F-PFN), was synthesized using a simple two-step reaction. A series of novel poly(ether ether ketone)s (PEEK-PFN-) containing perfluorononenyl groups were then prepared from 2F-PFN, resorcin, and 4,4'-difluorobenzophenone by nucleophilic polycondensation. The resulting copolymers were found to have different electric and thermal properties depending on the molar ratio of perfluorononenyl groups.