3- bromo-3-phenyl-3//-diazirine

To a solution of NaOEt (0.68 g, 10 mmol) in EtOH (10 mL), was added ethyl o-hydroxycinnamate (1.92 g, 10 mmol), and after dissolution of the phenolate formed, the mixture was taken to dryness. A solution of 3-bromo-3-phenyl-3//-diazirine (1.96g, 10 mmol) in dry hexane (17.3 mL) was added in one portion to a solution of the Na salt of ethyl 2-hydroxycinnamate in dry DMF (10 mL) under argon at rt. The mixture was stirred overnight. Normal workup (Et20, 1 M cold aq NaOH) and flash chromatography (hexane/EtjO 10 1.5) gave 2.28 g (82%) of the product as a colorless oil. 

For example, 3-bromo-3-phenyl-3//-diazirine was photolyzed with propenenitrile or... 

O-acyl thiohydroxamates was initially thwarted by competing ionic reactions but eventually culminated in the introduction of 3-bromo or 3-(trifluoromethyl)-3-phenyl diazirine as extremely effective reagents [27]. In contrast to almost all of the other reactions of Barton esters described in this chapter, however, the reaction sequence does not involve a chain process. Thus, as outlined in Scheme 25, capture of the alkyl radical by the diazirine is followed by dimerization and subsequent loss of nitrogen to give the product imine from which the desired amide or amine is easily liberated by mild hydrolysis. Some typical yields are shown in the Scheme 26. 

Bromo-2-butyl-1 -(4-trifluorome-thyl-phenyl)- El7a. 570 (Br — Ar- 311 -diazirin + 1-Hexen)... 

Thermal decomposition of 3-bromo-3-phenyl-37/-diazirine in the presence of an alkene has also been described. ... 

However, 1-acetoxy-1-phenylcyclopropanes can be synthesized by photolytic reaction of 3-acetoxy-3-phenyl-3//-diazirine (obtained from the corresponding bromo-diazirine and tetrabutylammonium acetate), with an alkcne. Excellent yields of acetoxycyclopropanes were obtained from alkenenitriles, e.g. 5, while a rather poor yield was obtained from 2-methylbut-2-... 

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