Reaktion von Arylhalogeniden mit Trialkylphosphiten und Benzolphosphonigsäure‐dialkylestern zu aromatischen Phosphonsäureestern und Phosphinsäureestern unter Nickelsalzkatalyse

Abstract

w Ein neues Verfahren zur Herstellung dromaticcher Phosphonsaureester (1 -25) durch Reaktion von Arylhalogeniden mit Trialkylphosphiten in Cegenwart katalytischer Mengen Nickelchlorid oder -bromid wrrd beschrieben. Analog lassen sich aus Benzolphosphonigsaurediathylester aromatische Phosphinsauren bzw deren Ester (26 ~ 30) herstellen. A new method lor the preparation of aromatic phosphonates (1 25) by reaction of aryl halides with trialkyl phosphites in the presence of catalytic amountr of nickel chloride or bromide is described. Similarly aromatic phosphinic acids and esters (26 30) are prepared from diethyl beiizenephosphonites Aromatische Phosphonskuren bzw. deren Ester lassen sich uber die Diazoniumsalze I), uber aromatische metallorganische Reagentienz) sowie durch direkte ,,Phosphonierung" von Aromaten3) herstellen. Arylhalogenide sind gegenuber Trialkylphosphiten inert, die Darstellung von Arylphosphonsaureestern gelingt jedoch durch Photolyse von Aryljodiden und -bromiden in Trialkylphosphiten4).Vor kurzem wurde uber die Bildung von aromatischen Phosphonsaureestern aus Aryljodiden bzw. -bromiden, Trialkylphosphiten und Kupfer berichtets). In Fortsetzung dieser Arbeiten fanden wir nun, daB Nickelsalze Nix2 (X = Br, Cl) die Reaktion von Arylhalogeniden mit Trialkylphosphiten katalysieren. In guter Ausbeute werden aromatische Phosphonsaureester gebildet, welche sich leicht rein gewinnen lassen.ZweckmaiBig erhitzt man eine Suspension des Nickelsalzes (5 -10 Mol-"/,) in einem Bromaromaten auf 150--1 6 0 und tropft langsam Triathylphosphit zu. Die Reaktion A r -X + P(OC2H& , Ar-PO(OCZH& + C,H,-X(1) 1 50-160O

Carbonylation of Dinitrotoluene to Dimethyl Toluenedicarbamate; High Efficiency of Phosphorus Acids as Promoters for the Palladium-Phenanthroline Catalytic System

“…Use of gaseous HCl in this reaction to avoid the co-crystallization of water is not advisable, since a mixture of mono-and dichlorohydrate (with the second prevailing) was obtained with this reagent. 4-MeC 6 H 4 P(O)(OH) 2 and 4-ClC 6 H 4 P(O)(OH) 2 were synthesized by reaction of triethyl phosphite with 4-MeC 6 H 4 Br and 4-ClC 6 H 4 Br, respectively, in the presence of NiBr 2 , following the method of Tavs, [53] followed by hydrolysis of the ester with 37% HCl as reported. [54] They were characterized by comparison of their analytical data with those reported in the literature.…”

Phosphorus Acids as Highly Efficient Promoters for the Palladium‐Phenanthroline Catalyzed Carbonylation of Nitrobenzene to Methyl Phenylcarbamate†

“…[42] , and characterized by comparison of their analytical data with the published ones. [41,42] 2 , following the method of Tavs, [44] followed by hydrolysis of the ester with 37% HCl as in ref. [45] They were characterized by comparison of their analytical data with those reported in the literature.…”

Arylphosphonic acids. I. Substituent effects on their first and second dissociations

“…Most of the arylphosphonic acids were prepared in good yields by a published method that involves the treatment of the aryl iodide or bromide with triethyl phosphite at 180°C in the presence of anhydrous nickel bromide (26,27). The diethyl arylphosphonates so produced were hydrolyzed to the corresponding acids by refluxing them with concentrated hydrochloric acid for 6-8 h. The 3-and 4-carboxyphenylphosphonic acids were prepared in quantitative yields by starting with the corresponding methyl iodobenzoates.…”