(92) Divergent synthesis of methylene lactone- and methylene lactam-based spiro compounds; Utility of amido-functionalized γ-hydroxylactam as a precursor for cytotoxic N,O– and N,N-spiro compounds
Tetsuya Sengoku, Anna Shirai, Ayaka Takano, Toshiyasu Inuzuka, Masami Sakamoto, Masaki Takahashi and Hidemi Yoda
The Journal of Organic Chemistry, in press. (DOI: 10.1021/acs.joc.9b02038)
Pharmaceutically attractive methylene lactone- and methylene lactam-based spiro compounds have been synthesized by employing amido-functionalized γ-hydroxylactam as a common intermediate.
(91) Indium− and zinc−catalyzed enantioselective amide propargylation of aldehydes with stannylated allenyl amides
Tetsuya Sengoku, Ikuhei Ikeda, Keisuke Ai, Masaki Takahashi and Hidemi Yoda
Organic & Biomolecular Chemistry, 2019, 17, 2614-2618. (DOI: 10.1039/C9OB00040B)
A highly enantioselective allylation of aldehydes with newly prepared stannyl allenyl amides has been achieved using catalytic amounts of InCl3, ZnCl2 and a BINOL derivative.
(90) New synthetic methodology toward azaspiro-γ-lactones via oxidative C-H spirocyclization reaction
Tetsuya Sengoku, Yuichiro Nagai, Toshiyasu Inuzuka and Hidemi Yoda
Synlett, 2019, 30, 199-202. (DOI: 10.1055/s-0037-1611941)
The key C–H spirolactonization was accomplished by employing iodobenzene diacetate and potassium bromide to afford a variety of azaspiro-γ-lactones in high yields.
Journal Information: Impact factor 2.369 (Q2, JCR 2017)
(89) Electrophilic amide allylation of 3-heterosubstituted oxindoles: a new route to spirocyclic 2-oxindole containing α-methylene-γ-butyrolactam structure
Tetsuya Sengoku, Daichi Hayashi, Masaki Takahashi and Hidemi Yoda
European Journal of Organic Chemistry, 2018, 1813-1820. ()
The key “electrophilic amide allylation” was accomplished by using acetoxy methacrylamides and tetrakis(triphenylphosphine)palladium as a catalyst, affording a variety of the amide allylated products in excellent yields.
Journal Information: Impact factor 2.834 (Q2, JCR 2016)
(88) Controllable monobromination of perylene ring system: synthesis of bay-functionalized perylene dyes
Masaki Takahashi, Kyohei Asaba, Trinh Thi Lua, Toshiyasu Inuzuka, Naohiro Uemura, Masami Sakamoto, Tetsuya Sengoku and Hidemi Yoda
The Journal of Organic Chemistry, 2018, 83, 624-631. ()
Practical synthesis of bay-monofunctionalized perylene dyes has been developed based on controllable NBS bromination of tetrabenzyl perylene-3,4,9,10-tetracarboxylate. The ability to perform the convenient and high-yielding synthesis highlights the potential utility of our multifunctional approach to access diverse range of new perylene systems.
Journal Information: Impact factor 4.849 (Q1, JCR 2016)