1158430-75-1Relevant articles and documents
Synthesis of C2-symmetric bisphosphine ligands from tartaric acid, and their performance in the Pd-Catalyzed asymmetric o-allylation of a phenol
Dindaroglu, Mehmet,Akyol Dincer, Sema,Schmalz, Hans-Guenther
, p. 4315 - 4326 (2014/07/21)
Starting from tartaric acid derived chiral diols or dicarboxylic acid dichlorides with either a 2,2-dimethyl-1,3-dioxolane (Taddol) or a 2,3-dimethoxy-2,3-dimethyl-1,4-dioxane (Tatrol) core structure, and BH 3-protected ortho-phosphanyl phenols, a set of fourteen new C 2-symmetric diphosphine ligands was synthesized. In addition, three related ligands were obtained from ortho-diphenylphosphino-anilines. The fully characterized ligands were then tested in the Pd-catalyzed enantioselective O-allylation of 4-methoxyphenol using crotyl methyl carbonate as a reagent. In addition, a pseudo-intramolecular variant of the reaction, using crotyl 4-methoxyphenyl carbonate as a substrate, was studied. The so-called Trost ligand was used as a reference. Although the Trost ligand (3 mol-%) gave up to 84% ee, one of the new ligands showed higher activity (50% ee with 0.075 mol-%). Copyright
Modular synthesis of chiral phosphine-phosphite-ligands from phenolic precursors: A new approach to bidentate chelate ligands exploiting a P-O to P-C migration rearrangement
Velder, Janna,Robert, Tobias,Weidner, Ingo,Neudoerfl, Joerg-Martin,Lex, Johann,Schmalza, Hans-Guenther
supporting information; experimental part, p. 1309 - 1315 (2009/05/30)
An efficient and modular approach to bidentate phosphine-phosphite ligands formally derived from a 6-alkyl-2-phosphanylphenol, a chiral diol and phosphorus trichloride has been developed. In a key step, a borane-protected phosphinite, prepared from an o-b
