435269-67-3Relevant articles and documents
A diastereomeric pair of sulfoxide-containing chiral MOP-type ligands: Preparation and application to rhodium-catalyzed asymmetric 1,4-addition reactions
Hoshi, Takashi,Fujita, Masataka,Matsushima, Shouta,Hagiwara, Hisahiro,Suzuki, Toshio
supporting information, p. 800 - 802 (2018/06/12)
(R,SS)-Sulfoxide-MOP (L2) and (R,RS)-sulfoxide-MOP (L3) were developed as a diastereomeric pair of sulfoxide-containing chiral MOP-type ligands. These two ligands also represent the first monosulfoxide analogues of BINAP. The chiral ligand L2 was successfully applied to the highly enantioselective rhodium-catalyzed 1,4-addition between α,β-unsaturated ketones or esters and arylboronic acids, and exhibited a broad substrate scope when the reaction was performed using 1.5 mol% Rh in cyclohexane/H2O (10:1) at 40 °C under mild basic conditions.
Role of Regioisomeric Bicyclo[3.3.0]octa-2,5-diene Ligands in Rh Catalysis: Synthesis, Structural Analysis, Theoretical Study, and Application in Asymmetric 1,2- and 1,4-Additions
Mühlh?user, Tina,Savin, Alex,Frey, Wolfgang,Baro, Angelika,Schneider, Andreas J.,D?teberg, Heinz-Günter,Bauer, Florian,K?hn, Andreas,Laschat, Sabine
supporting information, p. 13468 - 13480 (2017/12/26)
In order to study the impact of regioisomeric diene ligands on the formation and catalytic activity of Rh complexes, a series of C2- and CS-symmetric 2,5-disubstituted bicyclo[3.3.0]octa-2,5-dienes C2-L and CS-L, respectively, were synthesized from Weiss diketone by simultaneous deprotonation/electrophilic trapping of both oxo functions, and the catalytic behavior was studied in the presence of [RhCl(C2H4)2]2. Complexes [RhCl(C2-L)]2 bearing C2-symmetric ligands catalyzed effectively the asymmetric arylation of N-tosylaldimines to (S)-diarylamines with yields and ee values up to 99%. In Hayashi-Miyaura reactions, however, the complexes showed poor catalytic activity. When complexes [RhCl(CS-L)]2 with CS-symmetric ligand or mixtures of [RhCl(C2-L)]2 and [RhCl(CS-L)]2 were employed in 1,2-additions, racemic addition products were observed, suggesting a C=C isomerization of the diene ligands. X-ray crystal structure analysis of both Rh complexes formed from the [RhCl(C2H4)2]2 precursor and ligands C2-L and CS-L revealed that only the C2-symmetric ligand C2-L coordinated to the Rh, whereas CS-L underwent a Rh-catalyzed C=C isomerization to rac-C2-L, which then gave the racemic [RhCl(rac-C2-L)]2 complex. DFT calculations of the relative stabilities of the Rh complexes and the proposed intermediates provided a mechanistic rationale via Rh-mediated hydride transfer.
Phosphine-olefin ligands based on a planar-chiral (π-Arene)chromium scaffold: Design, synthesis, and application in asymmetric catalysis
Ogasawara, Masamichi,Tseng, Ya-Yi,Arae, Sachie,Morita, Tomotaka,Nakaya, Takeshi,Wu, Wei-Yi,Takahashi, Tamotsu,Kamikawa, Ken
supporting information, p. 9377 - 9384 (2014/07/21)
The NMR and X-ray crystallographic studies clarified that planar-chiral alkenylene-bridged (phosphino-π-arene)(phosphine)chromium complexes 3 were capable of coordinating to a rhodium(I) cation in a bidentate fashion at the (π-arene)-bound phosphorus atom
