Phosphite‐thioether/selenoether Ligands from Carbohydrates: An Easily Accessible Ligand Library for the Asymmetric Hydrogenation of Functionalized and Unfunctionalized Olefins

Abstract

A large family of phosphite‐thioether/selenoether ligands has been easily prepared from accessible L‐(+)‐tartaric acid and D‐(+)‐mannitol and applied in the M‐catalyzed (M=Ir, Rh) asymmetric hydrogenation of a broad number of substrates (46 in total). Its highly modular architecture has been crucial to maximize the catalytic performance. Improving most of the reported approaches, this ligand family presents a broad substrate scope. By selecting the ligand parameters high enantioselectivities (ee's up to 99 %) have therefore been achieved in a broad range of both, functionalized and unfunctionalized substrates. Interestingly, both enantiomers of the hydrogenation products can be usually achieved by changing the ligand parameters.

Development of a novel phosphoramidite-selenide ligand for Pd-catalyzed asymmetric allylic substitution

“…10 Despite these significant achievements, the application of these selenide ligands is mainly limited to the palladium-catalyzed allylic alkylation of methyl malonate, the 1,4-addition of organic zinc to unsaturated ketones and asymmetric hydrogenation. 11 Therefore, the development of new chiral selenide-containing ligands for variable asymmetric reactions as well as broad substrate scope is still in great need. 12…”

Recent Advances in the Enantioselective Synthesis of Chiral Amines via Transition Metal-Catalyzed Asymmetric Hydrogenation

“…Consequently, the development of more efficient ligands for a range of catalytic processes is still a vital research topic. During the past decade, new families of chiral phosphines, including monodentate phosphines, − bis­(aminophosphine)-type ligands, − phosphino-phosphite (P-OP), − phosphino-phosphoramidite, − spiroketal , or supramolecular-type − biphosphines, and others, , have found widespread use in the rhodium-catalyzed AH of N -acyl enamines . Among these, the past decade has witnessed the development of P -stereogenic electron-rich alkyl phosphines as highly proficient ligands. ,,− Figure shows the most relevant P -stereogenic ligands used in the rhodium-catalyzed AH of benchmark enamides (Table ).…”

Recent Developments in Transition-Metal-Catalyzed Asymmetric Hydrogenation of Enamides

“…The Rh complexes of the developed ligands successfully hydrogenated functionalized and unfunctionalized olefins, including challenging substrates such as 1,1′-disubstituted unfunctionalized olefins (not shown) and cyclic -enamides (Schemes 59 and 60). 61 The Ir/L38 combination catalyzed the hydrogenation of cyclic and acyclic -enamides, but the enantioinductions were to some extent lower in comparison to the Rh catalyst precursors (Scheme 61). Moreover, the Ir catalyst provided the opposite enantiomer compared to that of the Rh complex for cyclic -enamides, while hydrogenation of acyclic -enamides produced the same configuration.…”

“…Moreover, the Ir catalyst provided the opposite enantiomer compared to that of the Rh complex for cyclic -enamides, while hydrogenation of acyclic -enamides produced the same configuration. 61 In 2016, Lv, Zhang and co-workers reported the Rh/DuanPhos (L6)-catalyzed asymmetric hydrogenation of -dehydroamino ketones to efficiently produce the corresponding aliphatic -amino ketones (93-99% yield, 98 to >99% ee) that were converted into chiral pharmaceutical…”