Diazomethanes, stannyl

Reaction 42 shows the thermal rearrangement of bis(stannyl)diazomethanes into car-bodiimides, which can be further derivatized in many ways293. 

Stannyl diazo compounds are less reactive than their lithium analogues and, containing a bigger metal atom, strongly favor reaction at N to give nitrile imines (e.g., 155 from 154). The use of bis(trimethylstannyl)diazomethane (156) provides an easy one-step route to symmetrically substituted systems (e.g., 157). 

Photolysis of [bis(diisopropylamino)phosphanyl](stannyl)diazomethane derivatives at room temperature gave transient (phosphanyl)(stannyl)carbenes which, in the presence of methyl acrylate, afforded methyl 2-[bis(diisopropylamino)phosphanyl]-2-(stannyl)cyclopropanecarb-oxylates in good yield according to P NMR spectroscopy. ... 

The cycloaddition of diazoalkanes to alkynes gives pyrazoles the use of stannyl alkynes ° produces tin derivatives of the heterocycle (cf. 4.1.6), for use in subsquent electrophilic ipio-displacements, or in palladium(0)-catalysed couplings. Aryl-diazomethanes can be generated in situ, from tosylhydrazones, for formation of pyrazoles. ... 

The 1,3-dipolar cycloaddition of tributyl(3,3,3-trifluoro-l-propynyl)stannane 113 with diazomethane allowed the regioselective synthesis of 5-(tributyl)stannyl-4-trifluoromethylpyrazole 114 (Scheme 36) [59], and interesting building-block for the synthesis of a variety of 5-substituted 4-trifluoromethylpyrazoles by crosscoupling reactions (see Sect. 7.1). 

Synthesis of Thiono- and Dithio-esters.—Alkylation of Thio- and Dithio-carb-oxylates. Alkylation of thiocarboxylates takes place at the sulphur atom, and thiolesters are the reaction products in almost all cases. The reaction of thio-benzoic acid with diazomethane yields, however, some methyl thionobenzoate, along with a ten-fold amount of the thiolobenzoate, from which it may be cleanly separated by chromatography, On the other hand, silylation of monothio- or monoseleno-carboxylates affords the 0-silyl esters, in contrast to germylation or stannylation, which occur at the sulphur atom. 

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