Stannyl nitrates

Withasomnine Pyrazole, 1-phosphoryl-reactions, 5, 271 Pyrazole, 1-silyl-synthesis, 5, 236 Pyrazole, 1-stannyl-synthesis, 5, 236 Pyrazole, 1-styryl-synthesis, 5, 233 Pyrazole, 1-thienyl-reactions, 5, 268 Pyrazole, 4-(2 -thienyl)-nitration, 5, 238 Pyrazole, 4-(3 -thienyl)-nitration, 5, 238 Pyrazole, trifluoromethyl-synthesis, 5, 284... 

In a related context, 2-(/Koiuenesulfonyl)ethy]amine was used as an ammonia equivalent in an aza-ene reaction by which aldehyde 92.1 was converted to the bicycle 912 [Scheme 8.92].223 After N-acetylation and Pd(0)-catalysed hydro-stannylation, the alkenylstannane 914 dintensed under copper(II) nitrate catalysis. The 2-(p-toiuenesulfonyl)ethyl group was then discharged by p-elimination with potassium rm-butoxide. 

Nitration of benzo[i]thiophene has been achieved by treatment of trimethyl stannyl benzo[6]thiophene with tetranitromethane in the presence of light <03EJOC1711>. Amination of thiophene halides has been carried out using Pd(dba)2 <03JOC2861>. While the bromo derivatives have been reported to give moderate to high yields the chloro derivatives were found to give only 40-50 % yield. 

Polyethers are readily accessible by tandem radical cyclizations. For example, bis-allylether 480a,b reacts with a trimethyl tin radical and then undergoes a sequential radical cyclization to provide 481a,b in 86 and 85% yield, respectively (equation (13)) (92JA3115). A ceric ammonium nitrate oxidation of 481 was carried out in methanol and converted the stannyl moiety into the corresponding dimethylacetal. 

Chiral y-amino-acids (e.g. 180) have been prepared from the corresponding optically active /8-amino-acids by the addition of one carbon atom using the Arndt-Eistert reaction.w-Amino-acids are available from cyclic anhydrides by treatment with stannyl azide (to give an w-isocyanatocarboxylic acid) followed by addition of an alcohol. In contrast to simple enamines, oxidation of N-acyl-a-aminocrotonates with thallium nitrate leads to the corresponding a/8-dimethoxy derivatives. 

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