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4.4.40.30 Method 30: From Carboxylic Acid Derivatives and an Organocerium Reagent by a Peterson-type Reaction

DOI: 10.1055/sos-SD-004-00909

Sarkar, T. K.Science of Synthesis, (20024874.

2-Substituted allylsilanes have been prepared from carboxylic acid derivatives such as esters by exposure to a twofold excess of organocerium reagent, prepared in situ from [(trimethylsilyl)methyl]magnesium chloride and cerium(III) chloride, followed by a Peterson-type elimination of the resultant bis(silylmethyl)carbinols. This method has, for example, been used in the formation of silane 116 (Scheme 51).[‌181‌] Chiral 2-substituted allylsilanes, for example, 117,[‌182‌] as well as allylsilanes containing acid-sensitive functional groups, for example, 118[‌183‌,‌184‌] are also available by this method (Scheme 51). This procedure is equally applicable to lactones as substrates, as shown by the preparation of silane 119.[‌183‌,‌185‌] The trick for successful preparation of allylsilanes by this method is to use a good-quality Grignard reagent and anhydrous reaction conditions.[‌181‌,‌185‌] However, sterically highly congested esters, such as adamantane-1-carboxylate do not react under these conditions.[‌181‌] An analogous procedure using an organocerium reagent derivable in situ from [(trimethylsilyl)methyl]lithium and cerium(III) chloride has limited scope, and is suitable only for acid chlorides.[‌186‌]

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