1370729-71-7Relevant academic research and scientific papers
Catalytic asymmetric iodocyclization of N-tosyl alkenamides using aminoiminophenoxy copper carboxylate: A concise synthesis of chiral 8-oxa-6-azabicyclo[3.2.1]octanes
Arai, Takayoshi,Watanabe, Ohji,Yabe, Shinnosuke,Yamanaka, Masahiro
supporting information, p. 12767 - 12771 (2015/10/28)
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 of the [L7-Cu-OAc] acts as a base to generate the anion of N-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 O-iodocyclization of N-Tosyl alkenamides. An aminoiminophenoxy copper carboxylate-catalyzed asymmetric iodocyclization of N-Tosyl alkenamides gave O-cyclized products in good yields with high enantioselectivity. Chiral 8-oxa-6-azabicyclo[3.2.1]octanes were synthesized by a sequential reduction/cyclization process from the iodocyclization product. DFT calculations suggested that the N-tosyl alkenamides are activated by hydrogen bonding with a carboxylate anion on the copper center to allow iodo-O-cyclization.
A trinuclear Zn3(OAc)4-3,3′-bis(aminoimino) binaphthoxide complex for highly efficient catalytic asymmetric iodolactonization
Arai, Takayoshi,Sugiyama, Noriyuki,Masu, Hyuma,Kado, Sayaka,Yabe, Shinnosuke,Yamanaka, Masahiro
supporting information, p. 8287 - 8290 (2014/07/22)
A 3,3′-bis(aminoimino)BINOL ligand was newly designed and synthesized for the formation of a trinuclear Zn complex upon reaction with Zn(OAc) 2. Using the harmony of the tri-zinc atoms, 1 mol% Zn 3(OAc)4-3,3′-bis(aminoimin
Achiral counterion control of enantioselectivity in a Bronsted acid-catalyzed lactonization
Dobish, Mark C.,Johnston, Jeffrey N.
supporting information; experimental part, p. 6068 - 6071 (2012/05/07)
Highly enantioselective halolactonizations have been developed that employ a chiral proton catalyst-N-iodosuccinimide (NIS) reagent system in which the Bronsted acid is used at catalyst loadings as low as 1 mol %. An approach that modulates the achiral counterion (equimolar to the neutral chiral ligand-proton complex present at low catalyst loadings) to optimize the enantioselection is documented for the first time in this transformation. In this way, unsaturated carboxylic acids are converted to γ-lactones in high yields (up to 98% ee) using commercially available NIS.
