12 research outputs found
Désaromatisation oxygénante asymétrique de phénols à l'aide d'iodanes pour la synthÚse totale de substances naturelles
The oxygenative phenol dearomatization reaction is a very useful transformation, as a key step in the synthesis of complex natural substances. It gives access to cyclohexa-2,4-dienones from ortho-substituted phenols, through the use of hypervalent iodine reagents (i.e., iodanes), which constitutes a modern alternative to toxic heavy-metal-based reagents (e.g., Pb, Tl, Hg). Our team is interested in the hydroxylative dearomatization of 2-alkylphenols (HPD reaction) by iodanes, a transformation that results in the formation of one quaternary stereogenic center. Control of the absolute configuration of this chiral center through the use of an appropriate substrate or reagent is amongst our goals. Chiral iodanes recently developed in the laboratory allowed us to reach enantiomeric excesses above 90 % in model HPD reactions. Successful application of these chiral iodanes led us to achieve the first total syntheses of (â)-bacchopetiolone and (+)-maytenone, as well as that of the epoxy ortho- quinol polar head of (+)-scyphostatine.La rĂ©action de dĂ©saromatisation oxygĂ©nante de phĂ©nols est une transformation trĂšs utile en tant quâĂ©tape clĂ© dans la synthĂšse de substances naturelles complexes. Elle permet de prĂ©parer des intermĂ©diaires de type cyclohexa-2,4-diĂ©nones Ă partir de phĂ©nols ortho-substituĂ©s, notamment en utilisant des rĂ©actifs iodĂ©s hypervalents (i.e., iodanes) qui constituent une alternative moderne aux rĂ©actifs Ă base de mĂ©taux lourds toxiques (e.g., Pb, Tl, Hg). Notre Ă©quipe sâintĂ©resse plus particuliĂšrement Ă la dĂ©saromatisation hydroxylante de 2-alkylphĂ©nols (rĂ©action HPD) par des iodanes, transformation qui engendre la crĂ©ation dâun centre carbonĂ© quaternaire stĂ©rĂ©ogĂšne. Le contrĂŽle de la configuration de ce centre chiral par lâutilisation dâun substrat ou dâun rĂ©actif appropriĂ© est un de nos objectifs. Des iodanes chiraux rĂ©cemment dĂ©veloppĂ©s au laboratoire ont permis dâatteindre des excĂšs Ă©nantiomĂ©riques de plus de 90% dans des rĂ©actions HPD modĂšles. Nous avons exploitĂ© avec succĂšs ces iodanes chiraux pour rĂ©aliser les premiĂšres synthĂšses totales de la (â)-bacchopĂ©tiolone et de la (+)-maytĂ©none, ainsi que pour Ă©laborer la tĂȘte polaire de type ortho-quinol Ă©poxydĂ© de la (+)-scyphostatine
Asymmetric oxygenative dearomatization of phenols promoted by iodanes for the total synthesis of natural products
La rĂ©action de dĂ©saromatisation oxygĂ©nante de phĂ©nols est une transformation trĂšs utile en tant quâĂ©tape clĂ© dans la synthĂšse de substances naturelles complexes. Elle permet de prĂ©parer des intermĂ©diaires de type cyclohexa-2,4-diĂ©nones Ă partir de phĂ©nols ortho-substituĂ©s, notamment en utilisant des rĂ©actifs iodĂ©s hypervalents (i.e., iodanes) qui constituent une alternative moderne aux rĂ©actifs Ă base de mĂ©taux lourds toxiques (e.g., Pb, Tl, Hg). Notre Ă©quipe sâintĂ©resse plus particuliĂšrement Ă la dĂ©saromatisation hydroxylante de 2-alkylphĂ©nols (rĂ©action HPD) par des iodanes, transformation qui engendre la crĂ©ation dâun centre carbonĂ© quaternaire stĂ©rĂ©ogĂšne. Le contrĂŽle de la configuration de ce centre chiral par lâutilisation dâun substrat ou dâun rĂ©actif appropriĂ© est un de nos objectifs. Des iodanes chiraux rĂ©cemment dĂ©veloppĂ©s au laboratoire ont permis dâatteindre des excĂšs Ă©nantiomĂ©riques de plus de 90% dans des rĂ©actions HPD modĂšles. Nous avons exploitĂ© avec succĂšs ces iodanes chiraux pour rĂ©aliser les premiĂšres synthĂšses totales de la (â)-bacchopĂ©tiolone et de la (+)-maytĂ©none, ainsi que pour Ă©laborer la tĂȘte polaire de type ortho-quinol Ă©poxydĂ© de la (+)-scyphostatine.The oxygenative phenol dearomatization reaction is a very useful transformation, as a key step in the synthesis of complex natural substances. It gives access to cyclohexa-2,4-dienones from ortho-substituted phenols, through the use of hypervalent iodine reagents (i.e., iodanes), which constitutes a modern alternative to toxic heavy-metal-based reagents (e.g., Pb, Tl, Hg). Our team is interested in the hydroxylative dearomatization of 2-alkylphenols (HPD reaction) by iodanes, a transformation that results in the formation of one quaternary stereogenic center. Control of the absolute configuration of this chiral center through the use of an appropriate substrate or reagent is amongst our goals. Chiral iodanes recently developed in the laboratory allowed us to reach enantiomeric excesses above 90 % in model HPD reactions. Successful application of these chiral iodanes led us to achieve the first total syntheses of (â)-bacchopetiolone and (+)-maytenone, as well as that of the epoxy ortho- quinol polar head of (+)-scyphostatine
Asymmetric oxygenative dearomatization of phenols promoted by iodanes for the total synthesis of natural products
La rĂ©action de dĂ©saromatisation oxygĂ©nante de phĂ©nols est une transformation trĂšs utile en tant quâĂ©tape clĂ© dans la synthĂšse de substances naturelles complexes. Elle permet de prĂ©parer des intermĂ©diaires de type cyclohexa-2,4-diĂ©nones Ă partir de phĂ©nols ortho-substituĂ©s, notamment en utilisant des rĂ©actifs iodĂ©s hypervalents (i.e., iodanes) qui constituent une alternative moderne aux rĂ©actifs Ă base de mĂ©taux lourds toxiques (e.g., Pb, Tl, Hg). Notre Ă©quipe sâintĂ©resse plus particuliĂšrement Ă la dĂ©saromatisation hydroxylante de 2-alkylphĂ©nols (rĂ©action HPD) par des iodanes, transformation qui engendre la crĂ©ation dâun centre carbonĂ© quaternaire stĂ©rĂ©ogĂšne. Le contrĂŽle de la configuration de ce centre chiral par lâutilisation dâun substrat ou dâun rĂ©actif appropriĂ© est un de nos objectifs. Des iodanes chiraux rĂ©cemment dĂ©veloppĂ©s au laboratoire ont permis dâatteindre des excĂšs Ă©nantiomĂ©riques de plus de 90% dans des rĂ©actions HPD modĂšles. Nous avons exploitĂ© avec succĂšs ces iodanes chiraux pour rĂ©aliser les premiĂšres synthĂšses totales de la (â)-bacchopĂ©tiolone et de la (+)-maytĂ©none, ainsi que pour Ă©laborer la tĂȘte polaire de type ortho-quinol Ă©poxydĂ© de la (+)-scyphostatine.The oxygenative phenol dearomatization reaction is a very useful transformation, as a key step in the synthesis of complex natural substances. It gives access to cyclohexa-2,4-dienones from ortho-substituted phenols, through the use of hypervalent iodine reagents (i.e., iodanes), which constitutes a modern alternative to toxic heavy-metal-based reagents (e.g., Pb, Tl, Hg). Our team is interested in the hydroxylative dearomatization of 2-alkylphenols (HPD reaction) by iodanes, a transformation that results in the formation of one quaternary stereogenic center. Control of the absolute configuration of this chiral center through the use of an appropriate substrate or reagent is amongst our goals. Chiral iodanes recently developed in the laboratory allowed us to reach enantiomeric excesses above 90 % in model HPD reactions. Successful application of these chiral iodanes led us to achieve the first total syntheses of (â)-bacchopetiolone and (+)-maytenone, as well as that of the epoxy ortho- quinol polar head of (+)-scyphostatine
Géoarchéologie des ports lagunaires en Méditerranée et en mer Noire
International audienc
Géoarchéologie des ports lagunaires en Méditerranée et en mer Noire
International audienc
Asymmetric Hydroxylative Phenol Dearomatization Promoted by Chiral Binaphthylic and Biphenylic Iodanes
International audienc
Total Synthesis of (â)-Bacchopetiolone via an Asymmetric Hydroxylative Phenol Dearomatization/[4+2]-Dimerization Cascade Promoted by a Novel Salen-Type Chiral Iodane
International audienceThe first total and biomimetic synthesis of the natural bis(sesquiterpene) (â)-bacchopetiolone (revised structure) was completed through a highly diastereoselective hydroxylative phenol dearomatization/[4+2]-dimerization cascade conversion of (+)-curcuphenol using a novel C2-symmetrical chiral Salen-type bis(λ5-iodane)
Bispericyclic Diels-Alder Dimerization of ortho-Quinols in Natural Product (Bio)Synthesis -Bioinspired Chemical 6-Step Synthesis of (+)-Maytenone
International audienc