32660-24-5Relevant articles and documents
Air-stable phosphine organocatalysts for the hydroarsination reaction
Leung, Pak-Hing,Li, Yongxin,Pullarkat, Sumod A.,Tay, Wee Shan,Yang, Xiang-Yuan
, (2020)
Readily-available triarylphosphines are explored as organocatalysts for the hydroarsination reaction. When compared to transition metal catalysis, phosphine organocatalysis greatly improved solvent compatibility of the hydroarsination of nitrostyrenes. Upon complete conversion, arsine products were isolated in up to 99% yield while up to 48% of the phosphine catalyst was still active. A mechanism was proposed and structure-activity analysis regarding catalyst activity concluded that sterically-bulkier catalysts were effective at minimizing catalyst deactivation.
Role of dppf Monoxide in the Transmetalation Step of the Suzuki-Miyaura Coupling Reaction
Payard, Pierre-Adrien,Bohn, Antoine,Tocqueville, Damien,Jaouadi, Khaoula,Escoude, Emile,Ajig, Sanaa,Dethoor, Annie,Gontard, Geoffrey,Perego, Luca Alessandro,Vitale, Maxime,Ciofini, Ilaria,Wagschal, Simon,Grimaud, Laurence
supporting information, p. 1120 - 1128 (2021/05/06)
Diphosphine ligands are frequently used in palladium-catalyzed Suzuki-Miyaura (S-M) reactions. Despite their widespread application in both academic and industrial settings, their role in the B-to-Pd transmetalation has not been firmly established. We combined electrochemistry, NMR spectroscopy, and DFT calculations to elucidate the role of dppf (1,1′-bis(diphenylphosphino)ferrocene) in this key elementary step of the S-M reaction. We observed that excess dppf inhibits transmetalation involving PhB(OH)2 and dppf-ligated arylpalladium(II) complexes, while an optimal [base]/[PhB(OH)2] ratio maximizes the concentration of a [Pd-O-B] key intermediate. In situ oxidation of dppf to the diphosphine monoxide dppfO can take place in the presence of base, leading to dppfO-ligated arylpalladium(II) complexes, which readily undergo transmetalation at room temperature. These findings suggest guidelines for the rational optimization of diphosphine-promoted S-M reactions.
Thiyl radical promoted chemo- and regioselective oxidation of CC bonds using molecular oxygen: Via iron catalysis
Xiong, Baojian,Zeng, Xiaoqin,Geng, Shasha,Chen, Shuo,He, Yun,Feng, Zhang
supporting information, p. 4521 - 4527 (2018/10/17)
The first example of the thiyl radical promoted ligand-free iron-catalyzed oxidative cleavage of alkenes using molecular oxygen (1 atm) has been developed. The reaction proceeds under mild reaction conditions with high efficiency and high chemo- and regioselectivity. It features a broad substrate scope and excellent functional group compatibility, enabling facile access to valuable molecules for application in medicinal chemistry. Preliminary mechanistic studies reveal that a vital intermediate dioxetane might be involved in the reaction and a thiyl radical plays a synergistic role in facilitating the selective oxidation of the CC bond.