Some Aminocyclopropane Chemistry and some Organotitanium Games with Alkynes

International audienc

Design and Implementation of a Non-biomimetic Strategy for the Synthesis of Kingianins, Original Malaysian Natural Products

International audienceKingianins are a family of unique natural products isolated from the bark of Endiandra kingiana, a tree growing in Malaysia.[1] These compounds are considered as promising hits for future applications in the context of the fight against cancer. Indeed, they exhibit significant binding affinity for Bcl-xL. As such, they are potentially valuable agents as inhibitors of this macromolecule, as well as of other anti-apoptotic proteins. To the synthetic organic chemist, their unusual pentacyclic structures, featuring two cyclobutane rings, is a daunting challenge and an additional incentive. A few groups have reported total syntheses of some members of the kingianin family.[2] All these syntheses implement a biomimetic strategy. The latter is not flexible and suffers from inherent selectivity problems that cause several steps to be low yielding. To overcome these hurdles, we have chosen a novel approach aimed at the expedient controlled synthesis of the natural product targets, as well as simplified analogues thereof. Warm and special thanks are addressed to Prof. Khalijah Awang (University of Malaya, Malaysia) and Dr Marc Litaudon (ICSN, Gif-sur-Yvette, France) for their key invaluable contribution in the initial phases of the project and for having made this work possible.[1] a) A. Leverrier, M. E. Tran Huu Dau, P. Retailleau, K. Awang, F. Guéritte, M. Litaudon, Org. Lett. 2010, 16, 3638–3641; b) A. Leverrier, K. Awang, F. Guéritte, M. Litaudon, Phytochemistry 2011, 72, 1443–1452; c) M. N. Azmi, C. Gény, A. Leverrier, M. Litaudon, V. Dumontet, N. Birlirakis, F. Guéritte, K. H. Leong, S. N. Abd. Halim, K. Mohamad, K. Awang, Molecules 2014, 19, 1732–1747; d) M. N. Azmi, T. Péresse, C. Remeur, G. Chan, F. Roussi, M. Litaudon, K. Awang, Fitoterapia 2016, 109, 190–195.[2] a) H. N. Lim, K. A. Parker, Org. Lett. 2013, 15, 398–401; b) S. L. Drew, A. L. Lawrence, M. S. Sherburn, Angew. Chem. Int. Ed. 2013, 52, 4221–4224; c) J. C. Moore, E. S. Davies, D. A. Walsh, P. Sharma, J. E. Moses, Chem. Commun. 2014, 50, 12523–12525

A tribute to Professor Samir Zard

International audienceProfessor Samir Z. Zard A tribute.This special issue of Arkivoc is dedicated to Professor Samir Z. Zard, on the occasion of his new status as Emeritus researcher and in recognition of his outstanding contribution to synthetic organic chemistry.Published on line 05-15-2023 Arkivoc 2024 (ii) 20231495 Six, Y

Two “exotic” stories: Ti-Mediated Alkyne Cyclotrimerisation Reactions and a Synthetic Approach Towards Kingianin Natural Products

International audienc

Cyclobutanes and cyclopropanes: Methodological studies toward kingianin natural products

International audienc

Bicyclic Aminocyclopropanes as Precursors of Various Nitrogen-containing Polycyclic Systems

International audienceBicyclic aminocyclopropane compounds constitute a special class of strained molecules which can undergo cyclopropane-ring opening under a variety of conditions [1,2]. During this talk, several examples will be presented, obtained in our group over the last few years [3-5]. The mechanisms of these reactions involve the generation of iminium, enamine or azomethine ylid species.[1] V. A. Rassadin, Y. Six, Tetrahedron, 2016, 72, 4701-4757.[2] Y. Six in Targets in Heterocyclic Systems, O. A. Attanasi, P. Merino, D. Spinelli, Eds.; Società Chimica Italiana: Roma (2017); Vol. 21, pp. 277−307.[3] A. Wasilewska, B. A. Woźniak, G. Doridot, K. Piotrowska, N. Witkowska, P. Retailleau, Y. Six, Chem. Eur. J., 2013, 19, 11759-11767.[4] C. Chen, P. Kattanguru, O. A. Tomashenko, R. Karpowicz, G. Siemiaszko, A. Bhattacharya, V. Calasans, Y. Six, Org. Biomol. Chem., 2017, 15, 5364-5372.[5] A. Wolan, J. A. Kowalska-Six, H. Rajerison, M. Césario, M. Cordier, Y. Six, Tetrahedron, 2018, 74, 5248-5257. (“Barton Centennial Symposium in Print” special issue

Aminocyclopropane Chemistry for the Construction of Nitrogen containing Polycyclic Systems

International audienc

Aminocyclopropanes as Valuable Precursors of Nitrogen containing Polycyclic Systems

International audienceBicyclic aminocyclopropane compounds constitute a special class of strained molecules which can undergo cyclopropane-ring opening under a variety of conditions [1,2]. During this talk, several examples will be presented, obtained in our group over the last few years [3-6]. The mechanisms of these reactions involve the generation of reactive species, such as iminium, enamine or azomethine ylid derivatives.[1] V. A. Rassadin, Y. Six, Tetrahedron, 2016, 72, 4701-4757.[2] Y. Six in Targets in Heterocyclic Systems, O. A. Attanasi, P. Merino, D. Spinelli, Eds.; Società Chimica Italiana: Roma (2017); Vol. 21, pp. 277−307.[3] A. Wasilewska, B. A. Woźniak, G. Doridot, K. Piotrowska, N. Witkowska, P. Retailleau, Y. Six, Chem. Eur. J., 2013, 19, 11759-11767.[4] C. Chen, P. Kattanguru, O. A. Tomashenko, R. Karpowicz, G. Siemiaszko, A. Bhattacharya, V. Calasans, Y. Six, Org. Biomol. Chem., 2017, 15, 5364-5372.[5] A. Wolan, J. A. Kowalska-Six, H. Rajerison, M. Césario, M. Cordier, Y. Six, Tetrahedron, 2018, 74, 5248-5257 (“Barton Centennial Symposium in Print” special issue).[6] V. Šlachtová, N. Casaretto, L. Brulíková, Y. Six, submitted manuscript

Playing with Cyclopropanes and Cyclobutanes: from Ring-Expansion Studies to Natural Product Synthesis

International audienc

Cyclobutanes et cyclopropanes : chimiques vicissitudes en synthèse totale et en méthodologie

National audienc