1585160-50-4Relevant articles and documents
Conformational Preferences of a Tropos Biphenyl Phosphinooxazoline-a Ligand with Wide Substrate Scope
Bellini, Rosalba,Magre, Marc,Biosca, Maria,Norrby, Per-Ola,Pàmies, Oscar,Diéguez, Montserrat,Moberg, Christina
, p. 1701 - 1712 (2016)
Excellent enantioselectivities are observed in palladium-catalyzed allylic substitutions of a wide range of substrate types and nucleophiles using a bidentate ligand composed of oxazoline and chirally flexible biaryl phosphite elements. This unusually wid
An improved class of phosphite-oxazoline ligands for Pd-catalyzed allylic substitution reactions
Biosca, Maria,Salto, Joan,Magre, Marc,Norrby, Per-Ola,Pamies, Oscar,Dieguez, Montserrat
, p. 6033 - 6048 (2019/07/19)
A method for generation of Pd/phosphite-oxazoline catalysts containing an alkyl backbone chain has been successfully applied to Pd-catalyzed allylic substitution reactions. By carefully selecting the substituents at both the alkyl backbone chain and the oxazoline of the ligand, as well as the configuration of the biaryl phosphite group, high activities (TOF > 8000 mol substrate × (mol Pd × h)?1) and excellent enantioselectivities (ee's up to 99%) have been achieved for many hindered and unhindered substrates with a wide range of C-, O-, and N-nucleophiles (73 substitution products in total). Moreover, DFT and NMR studies of the key Pd-allyl complexes allowed us to better understand the origin of the excellent enantioselectivities observed experimentally. The useful application of the Pd/phosphite-oxazoline catalysts was demonstrated by the syntheses of many chiral carbobicycles, with multiples stereocenters, by simple sequential reactions involving Pd-allylic substitution and either 1,6-enyne cyclization or Pauson?Khand enyne cyclization.
Computationally guided design of a readily assembled phosphite-thioether ligand for a broad range of pd-catalyzed asymmetric allylic substitutions
Biosca, Maria,Margalef, Jèssica,Caldentey, Xisco,Besora, Maria,Rodríguez-Escrich, Carles,Saltó, Joan,Cambeiro, Xacobe C.,Maseras, Feliu,Pàmies, Oscar,Diéguez, Montserrat,Pericàs, Miquel A.
, p. 3587 - 3601 (2018/04/14)
A modular approach employing indene as common starting material, has enabled the straightforward preparation in three reaction steps of P-thioether ligands for the Pd-catalyzed asymmetric allylic substitution. The analysis of a starting library of P-thioether ligands based on rational design and theoretical calculations has led to the discovery of an optimized anthracenethiol derivative with excellent behavior in the reaction of choice. Improving most approaches reported to date, this ligand presents a broad substrate and nucleophile scope. Excellent enantioselectivities have been achieved for a range of linear and cyclic allylic substrates using a large number of C-, N-, and O-nucleophiles (40 compounds in total). The species responsible for the catalytic activity have been further investigated by NMR in order to clearly establish the origin of the enantioselectivity. The resulting products have been derivatized by means of ring-closing metathesis or Pauson-Khand reactions to further prove the synthetic versatility of the methodology for preparing enantiopure complex structures.
