for asymmetric [3+2] cycloaddition reactions. A silver complex prepared from silver bis(trimethylsilyl)amide (AgHMDS) and (R)‐DTBM‐SEGPHOS worked well in asymmetric [3+2] cycloaddition reactions of α‐aminoester Schiff bases with several olefins to afford the corresponding pyrrolidine derivatives in high yields with remarkable exo‐ and enantioselectivities. Furthermore, α‐aminophosphonate Schiff bases
Silver lining: Highly exo‐selective asymmetric [3+2] cycloaddition of α‐amino ester Schiff bases with activated olefins proceeds in the presence of AgHMDS/1. The α‐amino ester Schiff bases including those derived from aliphatic imines successfully reacted to afford the corresponding pyrrolidine derivatives in high yield with high exo‐ and enantioselectivities. EWG=electron‐withdrawing group, HMDS=
Metal Amides as the Simplest Acid/Base Catalysts for Stereoselective Carbon-Carbon Bond-Forming Reactions
作者:Yasuhiro Yamashita、Shū Kobayashi
DOI:10.1002/chem.201300908
日期:2013.7.15
paper, new possibilities for metalamides are described. Although typical metalamides are recognized as strong stoichiometric bases for deprotonation of inert or less acidic hydrogen atoms, transition‐metalamides, namely silver and copper amides, show interesting abilities as one of the simplestacid/basecatalysts in stereoselectivecarbon–carbon bond‐forming reactions.