Association of Halogen Bonding and Hydrogen Bonding in Metal Acetate-Catalyzed Asymmetric Halolactonization
Takayoshi Arai,
Kodai Horigane,
Ohji Watanabe,
Junki Kakino,
Noriyuki Sugiyama,
Hiroki Makino,
Yuto Kamei,
Shinnosuke Yabe,
Masahiro Yamanaka
Affiliations
Takayoshi Arai
Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan; Soft Molecular Activation Research Center (SMARC), Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan; Chiba Iodine Research Innovation Center (CIRIC), 1-33 Yayoi, Inage, Chiba 263-8522, Japan; Corresponding author
Kodai Horigane
Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
Ohji Watanabe
Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
Junki Kakino
Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
Noriyuki Sugiyama
Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
Hiroki Makino
Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
Yuto Kamei
Department of Chemistry, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8588, Japan
Shinnosuke Yabe
Department of Chemistry, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8588, Japan
Masahiro Yamanaka
Department of Chemistry, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8588, Japan; Research Center for Smart Molecules, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8588, Japan; Corresponding author
Summary: Cooperative activation using halogen bonding and hydrogen bonding works in metal-catalyzed asymmetric halolactonization. The Zn3(OAc)4-3,3′-bis(aminoimino)binaphthoxide (tri-Zn) complex catalyzes both asymmetric iodolactonization and bromolactonization. Carboxylic acid substrates are converted to zinc carboxylates on the tri-Zn complex, and the N-halosuccinimide (N-bromosuccinimide [NBS] or N-iodosuccinimide [NIS]) is activated by hydrogen bonding with the diamine unit of chiral ligand. Halolactonization is significantly enhanced by the addition of catalytic I2. Density functional theory calculations revealed that a catalytic amount of I2 mediates the alkene portion of the substrates and NIS to realize highly enantioselective iodolactonization. The tri-Zn catalyst activates both sides of the carboxylic acid and alkene moiety, so that asymmetric five-membered iodolactonization of prochiral diallyl acetic acids proceeded to afford the chiral γ-butyrolactones. In the total description of the catalytic cycle, iodolactonization using the NIS-I2 complex proceeds with the regeneration of I2, which enables the catalytic use of I2. The actual iodination reagent is I2 and not NIS. : Chemistry; Catalysis; Organic Synthesis; Stereochemistry Subject Areas: Chemistry, Catalysis, Organic Synthesis, Stereochemistry
