Synthesis of chiral ligands containing the N-(S)-α-phenylethyl group and their evaluation as activators in the enantioselective addition of Et2Zn to benzaldehyde

Pd-η3-C6H9 complexes of the Trost modular ligand: high nuclearity columnar aggregation controlled by concentration, solvent and counterion

“… 28 Aziridine [D 10 ]- 13 , obtained under Mitsunobu conditions, was converted to azide [D 10 ]- 14 . 29 After diastereoisomer separation, hydrogenolysis 30 gave ( S , S )-diamine [D 10 ]- 15 , which was coupled with acid [D 14 ]- 10 to afford Trost ligand [D 38 ]- 2 . The chloro-bridged dimer [D 18 ]- 16 , prepared 31 from [D 10 ]- 5 , was converted to cationic complex [D 9 ]- 17 , and then reacted with [D 38 ]- 2 to generate [( S , S )-[D 47 ]- 1 ][BAr F ] in good yield.…”

On the Synthesis of a Novel Chiral Phosphorodiamidic Acid Containing­ the α-Phenylethyl Moiety: Insights on its Conformation and Reactivity

“…In a first attempt to synthesize the desired phosphorodiamidic acid I , the conditions described by Akiyama and Terada for the preparation of related phosphoric acids were followed. 2 In particular, a two-reaction, one-pot protocol was explored involving the initial condensation of phosphorus oxychloride with the known diamine (1 S ,2 S ,1′ S ,2′ S )- 1 15b under refluxing toluene to generate the intermediate (1 S ,2 S ,1′ S ,2′ S )- 2 , 19 which was then treated with water in an attempt to achieve a nucleophilic substitution reaction at phosphorus via replacement of the chloride atom by the hydroxyl function. Intermediate (1 S ,2 S ,1′ S ,2′ S )- 2 was recovered instead of the desired phosphorodiamidic acid.…”

Carbanions and Electrophilic Aliphatic Substitution

“…111 It has been observed that the presence of the ee cyclohexane core gave better enantioselection, presumably owing to a more rigid transition state for the addition reaction in the former ligand.…”