Organic Chemistry: Current Research
Open Access

Development of cycloaddition reactions using 1, 4-zwitterionic intermediates

4^th European Organic Chemistry Congress

March 01-03, 2018 | London, UK

Jun-ichi Matsuo

Kanazawa University, Japan

Scientific Tracks Abstracts: Organic Chem Curr Res

Abstract :

Cyclobutane derivatives show characteristic reactivities in organic reactions based on release of their high strained energy, and have been used as a useful C4 building block in organic synthesis. We found a new method for generation of 1,4-zwitterionic intermediates by Lewis-acid catalyzed ring cleavage of cyclobutanones which had a cation-stabilizing group at the 3-position.1 Regioselectivity for the ring cleavage was predicted and controlled by the structure of cyclobutanones. Formed 1, 4-zwitterionic intermediates reacted with compounds which had various types of unsaturated bonds such as C=C, Câ�?¡C, C=O, C=N, Câ�?¡N, N=N, N=O to give the corresponding six-membered compounds by formal [4+2] cycloaddition reaction.2,3 Reactions of the 1,4-zwitterionic intermediates with allenylsilanes and diene derivatives afforded seven- and eightmembered carbocyclic compounds by formal [4+3] and [4+4] cycloaddition reactions, respectively. Racemic total syntheses of thromboxane B2, bremazocine,4 and aspidospermidine5 were performed by using intra- and intermolecular cycloaddition of cyclobutanones. High reactivity of the zwitterionic intermediates for cycloaddition will be applicable to synthesis of multiply substituted cyclic compounds. Recent publications 1. Kuzuguchi T, Yabuuchi Y, Yoshimura T and Matsuo J (2017) Synthesis of multisubstituted phenols by formal [4+2] cycloaddition of nucleophilic alkynes with 3ethoxycyclobutanones. Org. Biomol. Chem 15:5268-5271. 2. Matsuo J (2014) 1, 4-Zwitterionic intermediates formed by cleavage of a cyclobutane ring and their cycloaddition reactions. Tetrahedron Lett 55:2589-2595. 3. Kawano M, Kiuchi T, Negishi S, Tanaka H and Hoshikawa T, (2013) Regioselective Inter- and Intramolecular Formal [4+2] Cycloaddition of Cyclobutanones to Indoles and Total Synthesis of (�?±)-Aspidospermidine. Angew. Chem., Int. Ed. 52:906-910. 4. Matsuo J, Okado R and Ishibashi H (2010) A new synthesis of 2,3-di- or 2,3,3-trisubstituted 2,3-dihydro-4-pyridones by reaction of 3-ethoxycyclobutanones and N-p-toluenesulfonyl imines using titanium(iv) chloride: Synthesis of (�?±)-bremazocine. Org. Lett. 12:3266-3268. 5. Matsuo J, Sasaki S, Tanaka H and Ishibash H (2008) Lewis acid-catalyzed intermolecular [4+2] cycloaddition of 3-alkoxycyclobutanones to aldehydes and ketones. J. Am. Chem. Soc. 130:11600-11601.

Biography :

Jun-ichi Matsuo received his PhD from Tokyo University under the direction of Prof. Kenji Koga and Prof. Sh�?« Kobayashi (1999). After his Postdoctoral research, he became an Assistant Professor at Tokyo University of Science (Prof. Teruaki Mukaiyama) in 2000. In 2002, he moved to the Kitasato Institute (Prof. Teruaki Mukaiyama and Prof. Satoshi Õmura). He moved to Kanazawa University as an Associate Professor in 2005, and was promoted to a Professor in 2014. His research interests include discovery and development of new organic reaction methodology.
Email:jimatsuo@p.kanazawa-u.ac.jp