Electronic Differences between Coordinating Functionalities of Chiral Phosphine-Phosphites and Effects in Catalytic Enantioselective Hydrogenation was written by Suarez, Andres;Mendez-Rojas, Miguel A.;Pizzano, Antonio. And the article was included in Organometallics in 2002.HPLC of Formula: 205927-03-3 This article mentions the following:
A convenient synthesis of new chiral phosphine-phosphites (P-OP) was described. The versatility of the synthetic protocol developed gave ligands with different phosphine fragments and the choice of the stereogenic element location. Analyses of the values of 1JPSe of the corresponding diselenides are in accord with the expected lower σ-donor ability of the phosphite fragment, with respect to the phosphine group, and with an increase of phosphine basicity after substitution of Ph substituents by Me groups. Inspection of υ(CO) values on complexes RhCl(CO)(P-OP) demonstrated a variable π-acceptor ability of the phosphite group, compensating for the change of basicity of the phosphine functionality, as well as having a rather reduced electron d. at the metal center compared with diphosphine analogs. The distinct nature of the P functionalities also was evidenced in Rh-catalyzed enantioselective hydrogenation of Me Z-α-acetamidocinnamate (MAC). Thus, the coordination mode of the substrate is governed by the chiral ligand, directing the olefinic bond to a cis position with respect to the phosphite group, as demonstrated by NMR studies performed with [Rh(P-OP)(MAC)]+ complexes. In consequence, the phosphite group has a greater impact on the enantioselectivity of the product. However, the optical purity of the process also depends on the nature of the phosphine group, and hence, an appropriate election of both P functionalities is required for the attainment of excellent enantioselectivities (99% ee). In the experiment, the researchers used many compounds, for example, (S)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol (cas: 205927-03-3HPLC of Formula: 205927-03-3).
(S)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol (cas: 205927-03-3) belongs to copper catalysts. Transition metal-catalyzed chemical transformation of organic electrophiles and organometallic reagents belong to the most important cross-coupling reaction in organic synthesis. These ligands enable the reaction promoted in mild condition. The reaction scope has also been greatly expanded, rendering this copper-based cross-coupling attractive for both academia and industry. HPLC of Formula: 205927-03-3
Referemce:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”