Joint ITC and DFT Study of the Affinity of Some Lewis Bases to HIFP in Solution

HFIP, i.e. 1,1,1,3,3,3-hexafluoropropan-2-ol, was found to be an exceptional medium,[1] either as solvent or co-solvent, that allows many reactions to occur.[2-5] However, the exact role and mode of action of HFIP in various chemical transformations still remains elusive. Despite many reports dealing with water/HFIP complexes, little has been published on other molecular complexes of HFIP as well as on thermochemistry of the formation of such complexes.[6] Within this study the affinity of a series of eight different Lewis bases (3 sulfoxides, 3 Nsp2 pyridine derivatives, 1 aromatic amine, 1 cyclic aliphatic ether) to HFIP (as Lewis acid) is investigated experimentally by Isothermal Titration Calorimetry (ITC) and theoretically using static DFT-D calculations. Measured ITC association enthalpy values ΔHaITC spanned -9.3 kcal/mol - -14 kcal/mol. Computations including a PCM implicit solvation model produced similar exothermicity of association of all studied systems - ΔHa values ranging -8.5 – -12.7 kcal/mol. In general, most of interaction energy is due to the hydrogen bonding and not due to formation of significantly strong halogen bonds. An additional set of calculations combining implicit and explicit solvation by chlorobenzene of the reactants, pointed out the relatively low interference of the solvent with the HFIPbase complexation, which main effect is to slightly enhance the Gibbs energy of the HFIP-Lewis base association. It is speculated that the interactions of bulk HFIP with Lewis bases therefore may significantly intervene in catalytic processes not only via the dynamic miscrostructuration of the medium but also more explicitly by affecting bonds’ polarization at the Lewis bases

Supplementary data for the article: Milovanović, M. R.; Dherbassy, Q.; Wencel‐Delord, J.; Colobert, F.; Zarić, S. D.; Đukić, J.-P. The Affinity of Some Lewis Bases for Hexafluoroisopropanol as a Reference Lewis Acid: An ITC/DFT Study. ChemPhysChem 2020, 21 (18), 2136–2142. https://doi.org/10.1002/cphc.202000560.

Supplementary material for: [https://doi.org/10.1002/cphc.202000560]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4337]Related to accepted version: [https://cherry.chem.bg.ac.rs/handle/123456789/4339

Stereoselective Metal-Catalyzed C–C Bond Coupling Reactions by Stereoconvergence, Dynamic Kinetic Asymmetric Transformation, or Dynamic Kinetic Resolution

International audienc

Synthèse des ligands chiraux DiPPAM et évaluation de leurs complexes métalliques pour la formation de liaison C-C

De nouveaux ligands chiraux tridentates P,N,O, les sels de phosphinoazométhinylate (les DiPPAMs), ont été développés. Une chimiothèque de 8 ligands a été synthétisée en une seule étape, sans aucune purification et avec des rendements quantitatifs. Des applications des DiPPAMs pour les réactions de couplages C-C ont été développées. De hautes énantiosélectivités ont été obtenues pour des additions conjuguées-1,4 et -1,6 catalysées au cuivre. Par ailleurs, un complexe Pd/DiPPAM a été isolé et évalué pour la réaction de Tsuji-Trostsur des substrats symétriques et dissymétriques. Des bons ee ont été obtenus dans le premier cas et un dédoublement cinétique a été observé lors d applications sur des substrats portant deux substituants différents sur les carbones allyliques terminaux.New chiral P,N,O ligands, the phosphinoazomethinaylate salts (DiPPAMs) were developed. A library of 8 DiPPAM ligands was prepared in one-step synthesis, without any purification and in quantitative yields. Applications of DiPPAMs for C-C bond formations were investigated. High enantioselectivities were obtained for 1,4- and 1,6-copper catalyzed conjugate additions. Furthermore, an original Pd/DiPPAM complex was synthesized and evaluated for Tsuji-Trost reaction on symmetric and dissymmetric substrates. Good ee s were obtained in the first case and a kinetic resolution was observed in the case of substrates bearing two different substituents on the external allylic carbones.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Highlights from the 54th EUCHEM Bürgenstock Conference on Stereochemistry, Brunnen, Switzerland, May 2019

International audienc

C–H bond activation enables the rapid construction and late-stage diversification of functional molecules

International audienc

Asymmetric C(sp 2 )H Activation

International audienc

Diastereoselective Substrate-Controlled Transition-Metal-Catalyzed C–H Activation: An Old Solution to a Modern Synthetic Challenge

International audienc