Triphenylphosphine-Catalyzed Dehydrogenative Coupling Reaction of Carboxylic Acids with Silanes – A Convenient Method for the Preparation of Silyl Esters
作者:Guo-Bin Liu、Hong-Yun Zhao、Thies Thiemann
DOI:10.1002/adsc.200600338
日期:2007.4.2
Triphenylphosphine has been found to be an efficient catalyst for the dehydrosilylation of carboxylic acids with silanes. In the presence of 4 mol % of triphenylphosphine (PPh3), dehydrosilylation reactions in DMF afforded the corresponding silyl esters at 120 °C in good yield.
REACTION OF STABLE TRIALKYLSILYL ESTERS WITH Ph<sub>3</sub>P(SCN)<sub>2</sub>: A NOVEL METHOD FOR THE PREPARATION OF ACYL AND AROYL ISOTHIOCYANATES UNDER NEUTRAL CONDITION
作者:N. Iranpoor、H. Firouzabadi、H. R. Shaterian
DOI:10.1081/scc-120014983
日期:2002.1
one-pot conversion of stable triisopropylsilyl- and tert-butyldimethylsilyl carboxylates to their corresponding acyl- or aroyl isothiocyanates using in-situ generation of Ph3P(SCN)2 at room temperature under neutral condition. This method has also been applied for the high yield preparation of 2-thioxo-3,4-dihydro-2H-1,3-benzoxazine-4-one, which has fungicidal and bactericidal activities.
EFFECTIVE SILYLATION OF CARBOXYLIC ACIDS UNDER SOLVENT-FREE CONDITIONS WITH <i>tert</i>-BUTYLDIMETHYLSILYL CHLORIDE (TBDMSCL) AND TRIISOPROPYLSILYL CHLORIDE (TIPSCL)
Various types of carboxylic acids can be converted effectively to their corresponding TBDMS and TIPS esters using TBDMSCI and TIPSCI in the presence of imidazole under solvent-free conditions. The advantage of this modified method in comparison with that reported by Corey is the elimination of DMF, which eliminates aqueous work-up. The method is not a time-consuming process and the reactions proceed spontaneously. By this method, absolute chemoselectivity for the protection of carboxylic acid functions in the presence of 2 degrees, 3 degrees hydroxyl groups are observed.
Two New Catalysts for the Dehydrogenative Coupling Reaction of Carboxylic Acids with Silanes—Convenient Methods for an Atom‐Economical Preparation of Silyl Esters
作者:Guo‐Bin Liu、Hong‐Yun Zhao、Thies Thiemann
DOI:10.1080/00397910701465669
日期:2007.8
Abstract Tris(triphenylphosphine)cuprous chloride [Cu(PPh3)3Cl] has been found to be an efficient catalyst for the dehydrosilylation of carboxylic acids with silanes. In the presence of 4 mol% Cu(PPh3)3Cl, dehydrosilylation reactions in acetonitrile afforded the corresponding silyl esters at 80°C in good yields. It was noted that triphenylphosphine itself also functions as an adequate catalyst for
carbonyl compounds, such as aldehydes, ketones, and amides. Furthermore, the porphyrinyl Grignard reagents underwent transmetalation to afford porphyrinyl copper and zinc species of mild and unique reactivity. These could be engaged in 1,4-addition and Negishi coupling, respectively.