Radical One-Pot α,β-Dual and β-Mono-Oxymethylation of Alkylidenemalonate

Dimethylzinc-mediated radical conjugate addition reaction of dimethyl alkylidenemalonates with iodomethyl pivalate gave a high yield of the α,β-dual oxymethylation product in one pot under air and the β-pivaloyloxymethylation product under argon

High Performance of <i>N</i>-Alkoxycarbonyl-imines in Triethylborane-Mediated Tin-Free Radical Addition

Triethylborane-mediated tin-free radical alkylation of <i>N-</i>alkoxycarbonyl-imines, such as <i>N-</i>Boc-, <i>N-</i>Cbz-, and <i>N-</i>Teoc-imines, proceeded smoothly at a low temperature (−78 to −20 °C) to give the corresponding adducts in high yield. Although the formation of isocyanate was the major unfavorable reaction at room temperature, a one-pot conversion of <i>N-</i>Boc-imine to <i>N</i>-ethoxycarbonyl-adduct was possible through the corresponding isocyanate generated in situ. The higher performance of <i>N-</i>alkoxycarbonyl-imine than those of <i>N</i>-Ts- and <i>N</i>-PMP-imines is rationalized by a moderate electron-withdrawing character of an alkoxycarbonyl group that makes both addition of alkyl radical and trapping of the resulting aminyl radical by triethylborane efficiently fast