This article reports the reaction of allyltrimethylsilane 1 with aldimines 2 in the presence of tetran-butylammonium fluoride to give the corresponding homoallylamines 3 in moderate to excellent yields. The allylation mechanism of imines as well as that of aldehydes can be reasonably interpreted by a fluoride-triggered autocatalytic procedure.
Ruthenium(II)-catalyzed reaction of
N-sulfonylimines with methyl isocyanoacetate proceeds
efficiently under neutral, mild conditions to give
trans-2-imidazolines stereoselectively in high
yields.
2,3-Diamino acids can be easily acquired via the hydrolysis of the
imidazolines in excellent yields.
A possible mechanism for the ruthenium-catalyzed aldol reaction of
the imines under neutral
conditions is discussed.
Under phase-transfer or low-temperature conditions, the ylide generated from diphenylsulfonium salt 2 readily reacts with N-sulfonylimines 1 to give acetylenylaziridines in excellent yields, but low to moderate cis/trans selectivity. When using n-BuLi as the base to generate the ylide at low termperature, product 3 with an intact silyl protecting group is obtained. t-BuOK, however, leads to desilylation product 4. With Cs 2 CO 3 as the base, dimethylsulfonium salts 6, 21, and 22 show much better cis/trans selectivity (>98:2) than diphenylsulfonium salt 2. The asymmetric version of the above aziridination reaction using camphor-derived sulfonium salts 12-14 and 20 gives chiral aziridines with ee values up to 85%. Both (2R,3S)-(-)-3 and (2S,3R)-(+)-3 can be prepared from 12/20 or 13/14, respectively. Ylides produced from telluronium salt 7 failed to react with imine 1a at room temperature, but the reaction succeeded at low temperature. Arsonium ylides from 8 cannot react with N-sulfonylimines under both sets of conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.