680614-40-8Relevant academic research and scientific papers
A Three-Component, One-Pot Synthesis of Indolizidines and Related Heterocycles Via the [3+2] Cycloaddition of Nonstabilized Azomethine Ylides
Pearson, William H.,Stoy, Patrick,Mi, Yuan
, p. 1919 - 1939 (2004)
Nonstabilized azomethine ylides (i.e. those bearing only hydrogens or alkyl groups) can be generated from (2-azaallyl)stannanes and (2-azaallyl)silanes through an intramolecular N-alkylation/demetalation cascade. The resulting ylides undergo [3+2] cycloaddition with electron-poor or electron-rich dipolarophiles yielding indolizidines and related 1-aza[m.3.0]bicycloalkane systems in good yield. An in situ protocol allows for a one-pot, three-component synthesis of indolizidines. The (2-azaallyl) stannanes tolerate enolizable hydrogens in these cycloadditions, while (2-azaallyl)silanes do not. The mechanism of the cycloaddition cascade is clarified by a series of control experiments. The same (2-azaallyl)stannanes may be transmetalated by n-butyllithium to generate 2-azaallyl-lithiums, which also may undergo a [3+2] cycloaddition/N-alkylation cascade to form indolizidines.
