Catalytic Asymmetric Iodocyclization of<i>N-</i>Tosyl Alkenamides using Aminoiminophenoxy Copper Carboxylate: A Concise Synthesis of Chiral 8-Oxa-6-Azabicyclo[3.2.1]octanes
作者:Takayoshi Arai、Ohji Watanabe、Shinnosuke Yabe、Masahiro Yamanaka
DOI:10.1002/anie.201505748
日期:2015.10.19
A newly developed aminoiminophenoxy copper carboxylate (L7‐Cu‐OAc)‐catalyzed asymmetric iodocyclization of N‐Tosyl alkenamides gave O‐cyclized products in good yields with high enantioselectivity. From the O‐cyclized products, a skeletal transformation was succeeded in the synthesis of biologically important chiral 8‐oxa‐6‐azabicyclo[3.2.1]octanes. DFT calculations suggested that the acetoxy anion
一种新开发的氨基亚氨基苯氧基羧酸铜(L7 -Cu-OAc)催化的N-甲苯磺酰基烯酰胺的不对称碘环化反应,以高收率和高对映选择性提供了O环化产物。从O环化产物中,成功地合成了生物学上重要的手性8-氧杂-6-氮杂双环[3.2.1]辛烷。DFT计算表明,[ L7 -Cu-OAc]的乙酰氧基阴离子可作为生成N- Tosyl alkenamide底物阴离子的碱。交换的乙酸在催化剂和底物之间重建了新的氢键网络,从而实现了高效的不对称O-iodocyclization的Ñ -tosyl alkenamides。