Pivaloylnitrene. Reactions with olefins and dichloromethane solvent effect

Felt, G. Robert.; Lwowski, Walter

doi:10.1021/jo00863a021

Cited by 19 publications

(2 citation statements)

References 13 publications

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“…The degree of retention of stereochemistry in cyclopropane formation by carbenes or aziridine formation by nitrenes is a standard probe for singlet versus triplet reactivity, in which stereospecific addition is taken as an indication of singlet reactivity. ,,− Addition of cis - or trans -4-octene to acetonitrile solutions in the photolysis of 2 causes a drop in the yield of the ylide product 6 and formation of the aziridines 12a and 12b , with full retention of stereochemistry, in 72 or 44% yield, respectively (entries 7 and 8). These product data do not distinguish between a direct reaction between the singlet benzoylnitrene ( 1 4 ) and the alkene and the alternate possibilities of a reaction between the ylide 5 or 2 * and the alkenes.…”

Section: Resultsmentioning

confidence: 99%

Photochemistry of Sulfilimine-Based Nitrene Precursors: Generation of Both Singlet and Triplet Benzoylnitrene

et al. 2007

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Photolysis of N-benzoyl-S,S-diphenylsulfilimine or N-benzoyl dibenzothiophene sulfilimine produces PhNCO and also benzoylnitrene. Direct observation of the triplet nitrene, energetic differences between the singlet and triplet state of the nitrene, and oxygen quenching experiments suggest that the triplet nitrene derives from the triplet excited state of the sulfilimine precursors, rather than through equilibration of nearby singlet and triplet states of the nitrene itself. In acetonitrile, the formation of an ylide, followed by cyclization to the corresponding oxadiazole, is the predominant nitrene chemistry, occurring on the time scale of a few microseconds and few tens of microseconds, respectively. Trapping experiments with substrates such as cis-4-octene suggest that reactivity of the nitrene is mainly through the singlet channel, despite a fairly small energy gap between the singlet ground state and the triplet. Photolysis of N-benzoyl-S,S-diphenylsulfilimine or N-benzoyl dibenzothiophene sulfilimine produces PhNCO and also benzoylnitrene. Direct observation of the triplet nitrene, energetic differences between the singlet and triplet state of the nitrene, and oxygen quenching experiments suggest that the triplet nitrene derives from the triplet excited state of the sulfilimine precursors, rather than through equilibration of nearby singlet and triplet states of the nitrene itself. In acetonitrile, the formation of an ylide, followed by cyclization to the corresponding oxadiazole, is the predominant nitrene chemistry, occurring on the time scale of a few microseconds and few tens of microseconds, respectively. Trapping experiments with substrates such as cis-4-octene suggest that reactivity of the nitrene is mainly through the singlet channel, despite a fairly small energy gap between the singlet ground state and the triplet.

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Section: Resultsmentioning

confidence: 99%

Photochemistry of Sulfilimine-Based Nitrene Precursors: Generation of Both Singlet and Triplet Benzoylnitrene

et al. 2007

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“…Nitrene addition reactions have somewhat more scope when the reactions are carried out by azide photolysis; for example, the acylnitrene pivaloylnitrene adds in moderate yield and with good stereoselectivity to cis -alkenes when it is generated from pivaloyl azide by photolysis in dichloromethane. 41 Similarly p -cyanobenzoylnitrene, when generated by photolysis of the azide 21 in the presence of 2,5 -dihydrofuran, gives the aziridine 22 in moderate yield (Scheme 6.11 ). 42 This nitrene and other p -substituted benzoylnitrenes also react with C 60 to give fulleroaziridines such as 23 .…”

Section: Aziridines Via Nitrene Intermediatesmentioning

confidence: 99%