Diazomethane substitute trimethylsilyldiazomethane

Diazomethane Methane, diazo- (334-88-3), 69, 180, 182 Diazomethane substitute trimethylsilyldiazomethane, 68, 1... 

The use of trimethylsilyldiazomethane with methanol provides a less hazardous method for preparing methyl esters under mild conditions than ethereal diazomethane solution. Trimethylsilyldiazomethane is commercially available, obviating the need to synthesize diazomethane daily. It is a stable and safe substitute for either hazardous diazomethane or corrosive reagents containing boron trifluoride. 

The safe and stable diazomethane substitutes arylsulphonyldiazomethane and trimethylsilyldiazomethane have both been shown to be acylated by carboxylic acid chlorides. Subsequent Wolff rearrangement then provides new and safe alternatives for the Arndt-Eistert reaction (Scheme 59). 

In contrast to A5-phosphorus-substituted diazo derivatives, which have been known for a long time,22 the synthesis of the first o -diazophosphine was reported as recently as 1985.23 This compound, namely the [bis(diiso-propylamino)phosphino](trimethylsilyl)diazomethane la, was obtained by treatment of the lithium salt of trimethylsilyldiazomethane with 1 equiv of bis(diisopropylamino)chlorophosphine. 

Trimethylsilyldiazomethane, as a stable and safe substitute for hazardous diazomethane, is useful both as a reagent for introducing a Cj-unit and as a C-N-N synthon for the preparation of azoles. Many methods are described in the literature for the preparation of trimethylsilyldiazomethane, including the trimethylsilylation of diazomethane (7-74S), the alkaline decomposition of N-nitroso-N-(trimethylsilylmethyl)amides (25-61%) and the diazo group transfer reaction of trimethylsilylmethyllithium with p-toluenesulfonyl azide (38%). The present modified diazo group transfer method appears to be the most practical, high-yield, and large scale procedure for the preparation of... 

Podlech, I 1998. Trimethylsilyldiazomethane (TMS-CHNj) and lithiated trimethylsilydiazomethane—versatile substitutes for diazomethane. JPrafcf Chem. 340, 679-682. 

A one-pot synthesis of furan 2-substituted-3-carboxylic and 2-substituted-3,4-dicarboxylic esters was reported. Thus, reaction of an acyl isocyanate with trimethylsilyldiazomethane, a safe replacement for hazardous diazomethane, gave 2-substituted oxazoles, which were treated with dimethyl acetylenedicarboxylate or ethyl propiolate to afford the corresponding di- and trisubstituted furans in good yields <04S1359>. 

Trimethylsilyldiazomethane, Mc3SiCHN2, is regarded as a stable and safe substitute for diazomethane [213]. It is believed that the expected product, RCOOCH2SiMe3, is formed first, but quickly converted to the methyl ester (with displacement of Me3SiCH20CH3) by methanol present in the reaction mixture. 

Trimethylsilyldiazomethane is described as a safe, stable substitute for the hazardous diazomethane in the homologation of ketones [equation (12)]. ... 

---