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International audience; Propargylic carbonates were converted to indenes through a S N 2'/Alder-ene cascade triggered by organocopper reagents. The reaction tolerates different organocopper species generated either from organolithiums or Grignard reagents. A catalytic version of this strategy could be devised using either copper or iron catalysts. Attempts to transfer chirality from an enantioenriched substrate revealed a moderate chirality conversion because of a low discrimination between the two faces of the internal olefinic partner with these typical substrates. The theoretical investigation supports a concerted closed-shell mechanism and highlights the influence of the substituents on the activation parameters and on the synchronicity of C-H bond breaking and CC bond forming during the Alder-ene step.

International audience; A novel series of enediynes possessing pentafluorophenylsulfoxide have been developed. The innovative compounds possess antiproliferative activity against a broad panel of human cancer cells originating from breast, blood, lung, kidney, colon, prostate, pancreas or skin with IC 50 ranging from 0.6 to 3.4 µM. The antiproliferative activity of enediynes in darkness is associated to their ability to compromise microtubule network. In addition, exposure to UV leads to double-stranded DNA cleavage caused by the newly synthesized molecules reducing further their IC 50 in nanomolar range against human tumor cells, including chemo-resistant pancreatic cancer cells. Taken together, the examined data demonstrate that enediynes possessing pentafluorosulfoxide are promising molecules in the cancer therapy.

An original synthesis of chiral benzofulvenes triggered by organocopper reagents is reported. These enantiopure products are available through a highly chemo-, regio-, diastereo-, and enantioselective bis(alkylating) cycloisomerization process. A double chirality transfer (central-to-axial-to-central) is observed.

The indanyl core is ubiquitous in a large variety of drugs and natural products. Importantly, the ever-increasing demand for chiral catalysts bearing this scaffold calls for state of the art methods allowing for a step-economical enantioselective access to this structural motif. We herein summarize the asymmetric syntheses of indanes with a particular focus on asymmetric catalysis, covering the literature of the last decade until July 2015.

International audience; The conversion of propargylic carbonates into allenes via Pd-catalyzed coupling with arylboronic acids, followed by tandem intramolecular Alder-ene cyclization, proceeds with remote diastereocontrol in the formation of indenes possessing two stereogenic elements (stereocenter and chiral axis). Highly configurationally stable atropisomers have been obtained with dr values up to >98:2. The reaction tolerates a range of commercially available functionalized arylboronic acids and allows the creation of C(sp2)–C(sp2) and C(sp2)–C(sp3) bonds in a single operation. Control experiments suggest that synergetic thermal and Pd-catalyzed cyclizations are likely to be involved in the second elementary step.

The indanyl core is ubiquitous in a large variety of drugs and natural products. Importantly, the ever-increasing demand for chiral catalysts bearing this scaffold calls for state of the art methods allowing for a step-economical enantioselective access to this structural motif. We herein summarize the asymmetric syntheses of indanes with a particular focus on asymmetric catalysis, covering the literature of the last decade until July 2015.

International audience; Organocopper reagents react with readily available chiral conjugated diene-ynes to give indene derivatives bearing two stereogenic centres. The investigation of this original reaction in optically pure series demonstrates that a double transfer of chirality is operating. A stereocontrolled cascade involving S(N)2' followed by carbocupration and conjugate addition reactions accounts for the total recovery of the initial chirality. The scope and limitations of the reaction were investigated. The high diastereofacial discrimination in the cyclisation step allowed the construction of the quaternary stereocentre with excellent dr and ee, with the opposite configuration depending on the E- or Z-configuration of the alkene in the starting material. Post-functionalisation of indenes allowed the synthesis of indanyl derivatives containing four contiguous stereocentres.