Bamford-Stevens reaction sulfonylhydrazone decomposition

Carbenes produced by photolysis of diazoalkanes are highly energetic species and often react indiscriminately. Thermal decomposition of diazoalkanes can be catalysed by certain transition metal (particularly copper or rhodium) salts, to produce less energetic and more selective carbenes. The active species in such a reaction is thought to be the metallocarbene rather than the free carbene. Another convenient and widely used route to alkylcarbenes is the thermal or photolytic decomposition of the lithium or sodium salts of toluene-p-sulfonylhydrazones. The diazoalkane is first formed (by elimination of the toluenesulfinate anion) and decomposes imder the reaction conditions to give the carbene (4.76). This process is often referred to as the Bamford-Stevens reaction. 

The synthesis of sulfones has been performed by iron-catalysed decomposition of sulfonylhydrazones. As commonly accepted for the related Bamford Stevens reaction, the reaction is thought to proceed through generation of a diazocompound by base-mediated thermal decomposition of the sulfonylhydrazone, leading to an intermediate iron carbenoid (65), which forms the sulfone (66) when trapped by the sulflnate anion released in the first step (Scheme 9). 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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