Synthesis of Sulfonyl Chlorides of Phenylboronic Acids

Abstract

Sulfonyl chlorides of phenylboronic esters have been made available by selective lithiation of bromo N-methyl-diethanolamine phenylboronates to give lithium sulfinyl phenylboronates as intermediates. Oxidations with N-chlorosuccinimide give the target sulfonyl chlorides, which may be isolated or used in situ for further reactions. The novel reagents are useful in preparation of among other sulfonamides of phenylboronic acids for use in Pd(0) catalysed cross-couplings. They also hold potential as carbohydrate binders with physiological pK a .

Synthesis of sulfonamide- and sulfonyl-phenylboronic acid-modified silica phases for boronate affinity chromatography at physiological pH

“…As an alternative a commercially available 4-mercaptophenylboronic acid was also chosen as a starting material. However, in the present work, attempts to convert the 4-mercaptophenylboronic acid to sulfonamide-phenylboronic acid 3 via a lithium sulfonyl phenylboronic acid intermediate [19] and to sulfonyl-phenylboronic acid 6 by oxidation of its sulfide intermediates with peroxide were unsuccessful, due to the deboronation and the conversion of phenylboronic acid to phenol.…”

A general method for the preparation of perfluoroalkanesulfonyl chlorides

“…At this point we were attracted by a report by Vedsø et al describing the oxidation of lithium arylsulfinate salts to the corresponding arylsulfonyl chlorides using N-chlorosuccinimide [13]. Following this literature precedent, sodium perfluorobutanesulfinate (4) was suspended in dichloromethane and treated with excess N-chlorosuccinimide.…”

Preparation and Screening of Diboronate Arrays for Identification of Carbohydrate Binders

“…This may be explained by unintended cross-linking of the resin by formation of boronic anhydrides. The availability of carboxylic acid and sulfonyl chlorides of phenylboronic acids [13] enables the solid-phase construction of diboronates by N-acylation and N-sulfonylation of Fmoc-Lys(Boc) and related diamines by an orthogonal protection scheme. The carboxy function of the chosen scaffolds serves both as handle for resin attachment and for potential attachment of new sensors to e.g.…”

“…The boronate phenylsulfonyl chlorides were prepared as described [13]. Resins and amino acids derivatives were purchased from Neosystems (France), Novabiochem or Bachem (Switzerland).…”

“…The high pKa of simple phenylboronic acids preclude their use at physiological conditions, but this problem can be corrected by introduction of electron-withdrawing groups, which lower the pKa of the boronic acid, or ortho-aminomethyl substituents, which ensure tetrahedral configuration at neutral pH by way of a non-covalent B-N interaction [6]. With regard to electron-withdrawing groups, both carboxy [7,8], nitro [9,10], cyano [11], pyridinium [12] and recently also sulfonamide substituents [13] have been employed. Ortho-aminomethyl boronic acids are in our experience often poorly soluble in water, and generally annoying to work with in multi-step synthetic procedures due to their zwitter-ionic character [10].…”