849604-79-1Relevant articles and documents
Half-sandwich ruthenium(ii) complexes with tethered arene-phosphinite ligands: Synthesis, structure and application in catalytic cross dehydrogenative coupling reactions of silanes and alcohols
González-Fernández, Rebeca,Crochet, Pascale,Cadierno, Victorio
, p. 210 - 222 (2019/12/28)
The preparation of the tethered arene-ruthenium(ii) complexes [RuCl2{η6:κ1(P)-C6H5(CH2)nOPR2}] (R = Ph, n = 1 (9a), 2 (9b), 3 (9c); R = iPr, n = 1 (10a), 2 (10b), 3 (10c)) from the corresponding phosphinite ligands R2PO(CH2)nPh (R = Ph, n = 1 (1a), 2 (1b), 3 (1c); R = iPr, n = 1 (2a), 2 (2b), 3 (2c)) is presented. Thus, in a first step, the treatment at room temperature of tetrahydrofuran solutions of dimers [{RuCl(μ-Cl)(η6-arene)}2] (arene = p-cymene (3), benzene (4)) with 1-2a-c led to the clean formation of the corresponding mononuclear derivatives [RuCl2(η6-p-cymene){R2PO(CH2)nPh}] (5-6a-c) and [RuCl2(η6-benzene){R2PO(CH2)nPh}] (7-8a-c), which were isolated in 66-99% yield. The subsequent heating of 1,2-dichloroethane solutions of these compounds at 120 °C allowed the exchange of the coordinated arene. The substitution process proceeded faster with the benzene derivatives 7-8a-c, from which complexes 9-10a-c were generated in 61-82% yield after 0.5-10 h of heating. The molecular structures of [RuCl2(η6-p-cymene){iPr2PO(CH2)3Ph}] (6c) and [RuCl2{η6:κ1(P)-C6H5(CH2)nOPiPr2}] (n = 1 (10a), 2 (10b), 3 (10c)) were unequivocally confirmed by X-ray diffraction methods. In addition, complexes [RuCl2{η6:κ1(P)-C6H5(CH2)nOPR2}] (9-10a-c) proved to be active catalysts for the dehydrogenative coupling of hydrosilanes and alcohols under mild conditions (r.t.). The best results were obtained with [RuCl2{η6:κ1(P)-C6H5(CH2)3OPiPr2}] (10c), which reached TOF and TON values up to 117 600 h-1 and 57 000, respectively.
Cyanation of alcohols with diethyl cyanophosphonate and 2,6-dimethyl-1,4-benzoquinone by a new type of oxidation-reduction condensation
Masutani, Kouta,Minowa, Tomofumi,Hagiwara, Yoshiaki,Mukaiyama, Teruaki
, p. 1106 - 1117 (2007/10/03)
Cyanation of various alcohols by a new type of oxidation-reduction condensation is described. Primary alkyl diphenylphosphinites, 2,6-dimethyl-1,4-benzoquinone (DMBQ), and diethyl cyanophosphonate gave the corresponding nitriles in high yields. During the above experiment on cyanation of 4-phenylbutan-2-ol, the unexpected formation of a mixture of nitrile and isocyanide was observed. After careful examination of the reaction conditions, selective synthesis of isocyanides from secondary alcohols was successfully accomplished by the use of zinc oxide (ZnO) as an additive. Reaction of tertiary alcohols provided the corresponding isocyanides exclusively in the absence of an additive. Cyanation of optically active alcohols was tried in order to clarify the stereochemistry of this reaction, and the reaction was thus proved to proceed with the inversion of configuration.
Preparation of various carboxylic acid esters from bulky alcohols and carboxylic acids by a new type oxidation-reduction condensation using 2,6-dimethyl-1,4-benzoquinone
Mukaiyama, Teruaki,Kikuchi, Wataru,Shintou, Taichi
, p. 300 - 301 (2007/10/03)
A new-type oxidation-reduction condensation by using 2,6-dimethyl-1,4-benzoquinone (DMBQ), carboxylic acids and in situ formed alkoxydiphenylphosphines (1) including the bulky alkoxy group-substituted ones proceeded smoothly to afford the corresponding carboxylic acid esters in good to high yields. Alkoxydiphenylphosphines were formed in situ by treating either N,N-dimethylaminodiphenylphosphine (Ph2PNMe2) with primary or secondary alcohols or chlorodiphenylphosphine with the lithium salts of primary, secondary and tertiary alcohols.
