The Takao Group
   Department of Applied Chemistry, Keio University

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Research

Numerous organic compounds possessing important bioactivities and novel structures have been found in nature. Our group focuses on the total synthesis of such interesting natural products and their related compounds, and the development of stereoselective synthetic organic reactions.

 Completed Projects

• Formal Synthesis of (R)-(-)-Puraquinonic Acid
  

Keywords: asymmetric (3 + 2) cycloaddition; all-carbon quaternary stereocenter

1) Oga, M.; Takamatsu, Y.; Ogura, A.; Takao, K. J. Org. Chem. 2022, 87, 8788-8795.

• Red-Light-Mediated Barton-McCombie Reaction (with Dr. Ogura)
  

Keywords: photocatalyst; radical deoxygenation; red LEDs

1) Ogura, A.; Ichii, N.; Shibata, K.; Takao, K. Bull. Chem. Soc. Jpn. 2020, 93, 936-941. [Selected Paper]

• Synthesis of the Tricyclic Core of (-)-Callophycoic Acid A
  

Keywords: allylboration; radical cyclization; palladium-catalyzed reductive cyclization

1) Sakama, A.; Kameshima, R.; Motohashi, Y.; Sumida, W.; Unno, Y.; Yoshida, K.; Ogura, A.; Takao, K. J. Org. Chem. 2020, 85, 3245.

• Total Syntheses of (+)-Aquatolide and Related Humulanolides
  

Keywords: transannular [2+2] photocycloaddition; ring-opening/ring-closing/cross metathesis; intramolecular Nozaki-Hiyama-Takai-Kishi reaction

1) Takao, K.; Kai, H.; Yamada, A.; Fukushima, Y.; Komatsu, D.; Ogura, A.; Yoshida, K. Angew. Chem. Int. Ed. 2019, 58, 9851. [Highlighted in Synfacts 2019, 15, 971]

• Enantioselective Total Synthesis of (-)-Misramine (with Dr. Yoshida)
  

Keywords: organocatalysis; spiro compounds; alkaloids

1) Yoshida, K.; Fujino, Y.; Takamatsu, Y.; Matsui, K.; Ogura, A.; Fukami, Y.; Kitagaki, S.; Takao, K. Org. Lett. 2018, 20, 5044. [Highlighted in Synfacts 2018, 14, 1112]

• Total Synthesis and Structural Revision of Clavilactone D

Keywords: ring-opening/ring-closing metathesis; structure elucidation

1) Takao, K.; Nemoto, R.; Mori, K.; Namba, A.; Yoshida, K.; Ogura, A. Chem. Eur. J. 2017, 23, 3828.

2) Takao, K.; Mori, K.; Kasuga, K.; Nanamiya, R.; Namba, A.; Fukushima, Y.; Nemoto, R.; Mogi, T.; Yasui, H.; Ogura, A.; Yoshida, K.; Tadano, K. J. Org. Chem. 2018, 83, 7060.

• Organocatalytic Construction of Spiroindanes (with Dr. Yoshida)

Keywords: asymmetric catalysis; organocatalysis; spiro compounds

1) Yoshida, K.; Itatsu, Y.; Fujino, Y.; Inoue, H.; Takao, K. Angew. Chem. Int. Ed. 2016, 55, 6734. [Highlighted in Synfacts 2016, 12, 861]

• Total Synthesis of (+)-Cytosporolide A

Keywords: biomimetic synthesis; hetero-Diels-Alder reaction; o-quinone methide

1) Takao, K.; Noguchi, S.; Sakamoto, S.; Kimura, M.; Yoshida, K.; Tadano, K. J. Am. Chem. Soc. 2015, 137, 15971. [Highlighted in Synfacts 2016, 12, 222]

• Total Synthesis of (+)-Vibsanin A

Keywords: Barbier-type allylation; intramolecular Nozaki-Hiyama-Kishi reaction; Mitsunobu reaction

1) Takao, K.; Tsunoda, K.; Kurisu, T.; Sakama, A.; Nishimura, Y.; Yoshida, K.; Tadano, K. Org. Lett. 2015, 17, 756.

2) Sakama, A.; Nishimura, Y.; Motohashi, Y.; Yoshida, K.; Takao, K. Tetrahedron 2016, 72, 5465.

• Total Syntheses of (+)-Clavilactone A and (-)-Clavilactone B

Keywords: ring-opening/ring-closing metathesis; enantioselective alkynylation

1) Takao, K.; Nanamiya, R.; Fukushima, Y.; Namba, A.; Yoshida, K.; Tadano, K. Org. Lett. 2013, 15, 5582.

• Total Synthesis of (+)-Bakuchiol

Keywords: asymmetric Claisen rearrangement; all-carbon quaternary stereocenter

1) Takao, K.; Sakamoto, S.; Touati, M. A.; Kusakawa, Y.; Tadano, K. Molecules 2012, 17, 13330.

• Total Syntheses of (+)- and (-)-Pestalotiopsin A
  

Keywords: [2+2] cycloaddition; intramolecular Nozaki-Hiyama-Kishi reaction, caryophyllene sesquiterpenoid

1) Takao, K.; Hayakawa, N.; Yamada, R.; Yamaguchi, T.; Saegusa, H.; Uchida, M.; Samejima, S.; Tadano, K. J. Org. Chem. 2009, 74, 6452. [Selected as a Featured Article]
2)  Takao, K.; Hayakawa, N.; Yamada, R.; Yamaguchi, T.; Morita, U.; Kawasaki, S.; Tadano, K. Angew. Chem., Int. Ed. 2008, 47, 3426. [Highlighted in Synfacts 2008, 900]

• Total Syntheses of (+)-Mycoepoxydiene and (-)-1893A

Keywords: ring-opening/cross metathesis; ring-closing metathesis; oxygen-bridged cyclooctadiene

1) Takao, K.; Yasui, H.; Yamamoto, S.; Sasaki, D.; Kawasaki, S.; Watanabe, G.; Tadano, K. J. Org. Chem. 2004, 69, 8789.
2) Takao, K.; Watanabe, G.; Yasui, H.; Tadano, K. Org. Lett. 2002, 4, 2941.

• Total Syntheses of (+)-Cheimonophyllon E and (+)-Cheimonophyllal

Keywords: catalytic asymmetric Mukaiyama aldol reaction; bisabolane sesquiterpenoid

1) Takao, K.; Tsujita, T.; Hara, M.; Tadano, K. J. Org. Chem. 2002, 67, 6690.
2) Takao, K.; Hara, M.; Tsujita, T.; Yoshida, K.; Tadano, K. Tetrahedron Lett. 2001, 42, 4665.

• Total Syntheses of (+)-UPA0043 and (+)-UPA0044
  

 

Keywords: 6-endo cyclization via an epoxy ring opening; p-quinone methide

1) Takao, K.; Sasaki, T.; Kozaki, T.; Yanagisawa, Y.; Tadano, K.; Kawashima, A.; Shinonaga, H. Org. Lett. 2001, 3, 4291.