Distiboranes based on ortho-phenylene backbones as bidentate Lewis acids for fluoride anion chelation. Issue 22 (14th May 2021)

• Record Type: Journal Article
• Authors: You, Di; Zhou, Benyu; Hirai, Masato; Gabbaï, François P.
• Is Part Of: Organic & biomolecular chemistry. Volume 19:Issue 22(2021)
• Page Start: 4949
• Page End: 4957
• Publication Date: 2021-05-14
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d1ob00536g
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : We report a new approach to fluorinated distiboranes by reaction of ortho -phenylene distibines with octafluorophenanthra-9, 10-quinone. These new derivatives act as bidentate Lewis acids and readily chelate the fluoride anion. Abstract : As part of our efforts in the chemistry of main group platforms that support anion sensing and transport, we are now reporting the synthesis of anitmony-based bidentate Lewis acids featuring the o -C6 F4 backbone. These compounds can be easily accessed by reaction of the newly synthesized o -C6 F4 (SbPh2 )2 (5 ) with o -chloranil or octafluorophenanthra-9, 10-quinone, affording the corresponding distiboranes 6 and 7 of general formula o -C6 F4 (SbPh2 (diolate))2 with diolate = tetrachlorocatecholate for 6 and octafluorophenanthrene-9, 10-diolate for 7, respectively. While 6 is very poorly soluble, its octafluorophenanthrene-9, 10-diolate analog 7 readily dissolves in CH2 Cl2 and undergoes swift conversion into the corresponding fluoride chelate complex [7 -μ2 -F] − which has been isolated as a [ n Bu4 N] + salt. The o -C6 H4 analog of 7, referred to as 8, has also been prepared. Although less Lewis acidic than 7, 8 also forms a very stable fluoride chelate complex ([8 -μ2 -F] − ). Altogether, our experiental results, coupled with computational analyses and fluoride anion affinity calculations, show that 7 and 8 are some of the strongest antimony-based fluoride anion chelators prepared to date. Another notable aspect of this work concerns the use of the octafluorophenanthrene-9, 10-diolate ligand and its ablity to impart advantageous solubility and Lewis acidity properties.