Three‐step synthesis of arylpolyboronic acids from phenols via organotin compounds

Abstract

In this paper we describe a three‐step synthesis of aryldi‐ and triboronic acids starting from phenols. Several substituted phenols (I) were converted into the corresponding aryldiethylphosphates (II) in good to excellent yields. The latter, on reaction with sodium trimethylstannide in liquid ammonia, under irradiation, afforded the aryl‐ and heteroarylpoly(trimethylstannyl) derivatives in 65–90% yield. The third step is the reaction of the organotin compounds with borane in THF, which leads to the corresponding arylpolyboronic acids in around 80% yield. In order to confirm their structure, some of the diboronic acids were converted into the corresponding pinacol esters. The results obtained in a study on the synthesis of various terphenyls through double and triple Suzuki couplings catalyzed by palladium acetate between the obtained arylpolyboronic acids and various aryl halides are also reported. These reactions proceeded with an average 65% yield, and also enabled us to confirm the structures of some of the diboronic acids. The structure of the new compounds was determined by 1H, 13C and 119Sn NMR spectroscopy, mass spectrometry and IR spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.

Sonochemical synthesis of bis(tri-n-butylstannyl) aromatic compounds via Barbier-like reactions

“…In preliminary studies, the analysis by 119 Sn-NMR of the crude mixture obtained in this reaction showed the formation of 4 together with tri-n-butyltin bromide (5). However, after passing a solution of the crude product in ethyl acetate through a chromatographic column with silica gel doped with 10% of KF compound 4 was obtained pure.…”

“…Sn-NMR spectrum of the crude products before the treatment with silica gel doped with KF was also observed the formation of tri-n-butyltin bromide (5).…”

“…order to test the chemical reactivity of the aryl-and heteroarylbispolytributylstannylated compounds, we carried out Stille reactions with some of them. We found that the reaction between 1,4-bis(tri-n-butylstannyl)naphthalene (31) and piodotoluene (Scheme 9) in THF in the presence of catalytic amounts of palladium bis(triphenylphosphine) dichloride afforded the known 1,4-ditolylnaphthalene (44) [20] in 71% yield.…”

“…The synthesis of aromatic bis(stannylated) compounds is a very important target due to their [4] and also as starting material for Suzuki cross-coupling reactions [5].…”

Aromatic and Heteroaromatic Substitution by S RN 1 and S N 1 Reactions

“…Consequently, a variety of arylpolyboronic acids is achievable from the stannanes previously synthesized by the S RN 1 mechanism from ArCl or ArOH in around 80% yields [50,51]. Consequently, a variety of arylpolyboronic acids is achievable from the stannanes previously synthesized by the S RN 1 mechanism from ArCl or ArOH in around 80% yields [50,51].…”