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Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis : Novel ...

Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis : Novel ...

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Si – trialkylsilyl<br />

N<br />

OSi<br />

O<br />

Si<br />

SILYLATION OF NITRO COMPOUNDS AS A PROCESS 673<br />

Nu<br />

OSi<br />

N<br />

− Nu<br />

Nu′ −<br />

−OSi −<br />

−Nu'Si<br />

OSi<br />

Scheme 3.236<br />

OSi − + SiNu′ Nu −<br />

N<br />

−OSi −<br />

Nu<br />

O Nu′′−<br />

N OSi<br />

OSi− N O<br />

Si – trialkylsilyl SiOSi<br />

+<br />

B<br />

B<br />

Scheme 3.237<br />

Nu′′<br />

N OSi<br />

OSi<br />

A<br />

etc.<br />

N<br />

O −<br />

N<br />

Nu′′ OSi<br />

440<br />

+<br />

N(OSi)2<br />

detail (502). Accord<strong>in</strong>g to the <strong>in</strong>terpretation proposed by the authors, nucleophiles<br />

(Nu ′− ), as well as electrophiles, can <strong>in</strong>duce the transformation of BENAs <strong>in</strong>to<br />

conjugated nitrosoalkenes B (Scheme 3.237).<br />

The latter as Michael substrates can add a nucleophile at the β-C atom to<br />

give the anion of en-oxime A. It should be noted that different nucleophiles<br />

(Nu ′− <strong>and</strong> Nu ′− ) can be <strong>in</strong>volved <strong>in</strong> the Þrst <strong>and</strong> second attacks. F<strong>in</strong>ally, the<br />

anion A desilylates the next BENA molecule, which leads to the formation of

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