Ir/Thioether–Carbene, −Phosphinite, and −Phosphite Complexes for Asymmetric Hydrogenation. A Case for Comparison
作者:Pol de la Cruz-Sánchez、Jorge Faiges、Zahra Mazloomi、Carlota Borràs、Maria Biosca、Oscar Pàmies、Montserrat Diéguez
DOI:10.1021/acs.organomet.9b00514
日期:2019.11.11
of novel and simple Ir/thioether-NHC complexes in the asymmetric hydrogenation of unfunctionalized olefins and cyclic β-enamides. For comparison, we prepared and applied the analogues thioether–phosphinite/phosphite complexes. We found that the efficiency of the new Ir/thioether-NHC catalystprecursors varies with the type of olefin. Thus, while the Ir/thioether-NHC catalystprecursors provided lower
Lewis-Base-Catalyzed Reductive Aldol Reaction To Access Quaternary Carbons
作者:Yvonne C. DePorre、James R. Annand、Sukanta Bar、Corinna S. Schindler
DOI:10.1021/acs.orglett.8b00507
日期:2018.5.4
transformation relies on an electronically differentiated Lewis base catalyst, which is uniquely capable of promoting a reductive aldol reaction of α,α-disubstituted and α,α,β-trisubstituted enones. This approach provides a valuable synthetic alternative for carbon–carbonbond formation in complex molecular settings due to its orthogonal reactivity compared to that of traditional aldol reactions. Based on this
Enantioselective and Diastereoselective Conjugate Radical Additions to α-Arylidene Ketones and Lactones
作者:Changjia Zhao、Mukund Sibi
DOI:10.1055/s-0036-1590930
日期:2017.12
A highly stereoselective conjugate radicaladdition to arylidene ketones and lactones has been developed. The conjugate radicaladditionsusingchiral salen Lewis acids proceeds with up to 99:1 dr and 87% ee in good to excellent chemical yields.
已经开发了一种高度立体选择性的共轭自由基加成到亚芳基酮和内酯。使用手性萨伦路易斯酸的共轭自由基加成以高达 99:1 dr 和 87% ee 的良好化学产率进行。
Giving a Second Chance to Ir/Sulfoximine-Based Catalysts for the Asymmetric Hydrogenation of Olefins Containing Poorly Coordinative Groups
作者:Maria Biosca、Oscar Pàmies、Montserrat Diéguez
DOI:10.1021/acs.joc.9b00829
日期:2019.6.21
This work identifies a family of Ir/phosphite-sulfoximine catalysts that has been successfully used in the asymmetrichydrogenation of olefins with poorly coordinative or noncoordinative groups. In comparison with analogue Ir/phosphine-sulfoximine catalysts previously reported, the presence of a phosphite group extended the range of olefins than can be efficiently hydrogenated. High enantioselectivities
Alternatives to Phosphinooxazoline (<i>t-</i>
BuPHOX) Ligands in the Metal-Catalyzed Hydrogenation of Minimally Functionalized Olefins and Cyclic β-Enamides
privileged 4‐alkyl‐2‐[2‐(diphenylphosphino)phenyl]‐2‐oxazoline (PHOX) ligands by replacing the phosphine moiety by a biaryl phosphite group and/or the introduction of a methylene spacer between the oxazoline and the phenyl ring. The modular design of the ligands has given us the opportunity not only to overcome the limitations of the iridium‐PHOX catalytic systems in the hydrogenation of minimally functionalized