180589-80-4Relevant academic research and scientific papers
Development of novel hemilabile Segphos P-P=O ligands
Fukuda, Yoshimasa,Kondo, Kazuhiro,Aoyama, Toyohiko
, p. 955 - 956 (2007)
Development of novel chiral hemilabile Segphos P-P=O ligands is described. The ligands are examined for enantioselective Pd-catalyzed allylic alkylation of cyclic allylic acetates.
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.
Intramolecular Diels-Alder reaction of cyclenic trienes: Stereoselectivity and NMR structure determination
Blond, Alain,Platzer, Nicole,Guy, Alain,Dhotel, Helene,Serva, Laurence
, p. 283 - 293 (2007/10/03)
A series of trienes possessing an internally cyclenic dienophilic group undergo thermal intramolecular DielsAlder (IMDA) reaction with high selectivity for the cis-fused products. A concentrated solution of LIC1O4 in diethyl ether catalyzes the IMDA reaction of cyclenic nitrotrienes, giving rise to the irans-fused compounds. The stereochcmical outcome of these various processes are rationalized in terms of a minimization of the steric interactions between the ring and the chain on the one hand and the endo-stabilization from the nitro group on the other. The structures of the cycloadducts have been carefully determined by NMR 1H and 13C spectroscopy: dipolar interactions, detected via nuclear Overhauser effects, and criteria based on scalar coupling and moreover on chemical shifts have been employed. Conformational preferences were observed. Elsevier,.
