Catalytic Asymmetric Iodocyclization of N‐Tosyl Alkenamides using Aminoiminophenoxy Copper Carboxylate: A Concise Synthesis of Chiral 8‐Oxa‐6‐Azabicyclo[3.2.1]octanes. (14th September 2015)

• Record Type: Journal Article
• Authors: Arai, Takayoshi; Watanabe, Ohji; Yabe, Shinnosuke; Yamanaka, Masahiro
• Is Part Of: Angewandte Chemie. Volume 127:Number 43(2015)
• Page Start: 12958
• Page End: 12962
• Publication Date: 2015-09-14
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201505748
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A newly developed aminoiminophenoxy copper carboxylate (<bold>L7</bold>‐Cu‐OAc)‐catalyzed asymmetric iodocyclization of <italic>N</italic>‐Tosyl alkenamides gave <italic>O</italic>‐cyclized products in good yields with high enantioselectivity. From the <italic>O</italic>‐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 of the [<bold>L7</bold>‐Cu‐OAc] acts as a base to generate the anion of <italic>N</italic>‐Tosyl alkenamide substrates. The exchanged acetic acid reconstructs a new hydrogen‐bonding network between the catalyst and the substrates to accomplish the highly efficient asymmetric <italic>O</italic>‐iodocyclization of <italic>N</italic>‐Tosyl alkenamides.</p> </abstract>