Total synthesis and structural confirmation of (±)-spirocollequins A and B
Keita Ichikawa, Toshiyasu Inuzuka, Hidemi Yoda and Tetsuya Sengoku
Tetrahedron Letters 2022, 107, 154109. (DOI: 10.1016/j.tetlet.2022.154109)
The first total synthesis of antiplasmodial isoindolinone alkaloids, spirocollequins A and B, has been accomplished. The proposed structures of spirocollequins have been supported through the comparison of spectroscopic properties of the synthetic samples with those of natural products as well as single-crystal X-ray diffraction analysis using a synthetic precursor of spirocollequin B.
Copper sulfate-catalyzed asymmetric 1,4-addition of amido-functionalized allylboronates to maleimides in water
Tetsuya Sengoku, Takuto Kajihara, Mari Inaba and Hidemi Yoda
Asian Journal of Organic Chemistry 2022, 11, e202100773. (DOI: 10.1002/ajoc.202100773)
A new application of amido-functionalized allylboronates to asymmetric 1,4-addition in water has been developed. Extremely high enantioselective 1,4-addition was achieved by employing N-mesityl maleimide as a substrate under CuSO4/bis(oxazoline) catalysis, affording the adduct with >99% ee.
有機合成化学協会誌, 2021, 79, 829–838.
A heavy-metal-free desulfonylative Giese-type reaction of benzothiazole sulfones under visible-light conditions
Tetsuya Sengoku, Daichi Ogawa, Haruka Iwama, Toshiyasu Inuzuka and Hidemi Yoda
Chemical Communications, 2021, 57, 9858–9861. (DOI: 10.1039/D1CC03833H)
A heavy-metal-free desulfonylative Giese-type reaction has been achieved by using Hantzsch ester as a photoreductant under blue light.
Bifurcated synthesis of methylene-lactone- and methylene-lactam-fused spirolactams via electrophilic amide allylation of γ-phenylthio-functionalized γ-lactams
Tetsuya Sengoku, Koki Makino, Ayumi Iijima, Toshiyasu Inuzuka and Hidemi Yoda
Beilstein Journal of Organic Chemistry, 2020, 16, 2769–2775. (DOI: 10.3762/bjoc.16.227)
New synthetic methods for spirolactams bearing an α-methylene-γ-butyrolactone or its analogous methylene-lactam have been developed.
Development of new catalytic enantioselective formation of methylenelactam-based N,O-spirocyclic compounds via ring opening-asymmetric reclosure of hydroxylactams
Tetsuya Sengoku, Ayako Miyoshi, Tamaki Tsuda, Toshiyasu Inuzuka, Masami Sakamoto, Masaki Takahashi and Hidemi Yoda
Tetrahedron, 2020, 76, 131252. (DOI: 10.1016/j.tet.2020.131252)
Hydroxylactams prepared from N-carbonyl phthalimides and β-amido functionalized allylboronates underwent ring opening-asymmetric reclosure in the presence of catalytic amounts of MgBr2 and a chiral aminophenol to afford the corresponding N,O-spirocyclic compounds in excellent yields and high enantioselectivities.
Zinc Hydroxide‐Catalyzed Asymmetric Allylation of Acetophenones with Amido‐Functionalized Allylboronate in Water
Tetsuya Sengoku, Ryunosuke Maegawa, Hiroki Imamura, Mitsuo Wada and Hidemi Yoda
Advanced Synthesis & Catalysis, 2020, 362, 2397-2418. (DOI: 10.1002/adsc.202000195)
Enantioselective reaction of water‐stable amido‐functionalized allylboronates with acetophenone derivatives in water is reported. The reaction was catalyzed with zinc hydroxide and a didecylamino‐functionalized chiral aminophenol reagent, affording a variety of homoallylic alcohols in up to 99% yield. The enantiomeric excess of the product reached up to 98%.
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, 2019, 84, 12532-12541. (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.
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.
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)