50415-69-5Relevant articles and documents
Palladium-Catalyzed Asymmetric Markovnikov Hydroxycarbonylation and Hydroalkoxycarbonylation of Vinyl Arenes: Synthesis of 2-Arylpropanoic Acids
Guan, Zheng-Hui,Ren, Zhi-Hui,Wang, Yuan,Yang, Hui-Yi,Yao, Ya-Hong,Zou, Xian-Jin
supporting information, p. 23117 - 23122 (2021/09/18)
Asymmetric hydroxycarbonylation is one of the most fundamental yet challenging methods for the synthesis of carboxylic acids. Herein, we reported the development of a palladium-catalyzed highly enantioselective Markovnikov hydroxycarbonylation of vinyl arenes with CO and water. A monodentate phosphoramidite ligand L6 plays vital role in the reaction. The reaction tolerates a range of functional groups, and provides a facile and atom-economical approach to an array of 2-arylpropanoic acids including several commonly used non-steroidal anti-inflammatory drugs. The catalytic system has also enabled an asymmetric Markovnikov hydroalkoxycarbonylation of vinyl arenes with alcohols to afford 2-arylpropanates. Mechanistic investigations suggested that the hydropalladation is irreversible and is the regio- and enantiodetermining step, while hydrolysis/alcoholysis is probably the rate-limiting step.
Transition metal-free direct dehydrogenative arylation of activated C(sp3)-H bonds: Synthetic ambit and DFT reactivity predictions
Lovato, Kaitlyn,Guo, Lirong,Xu, Qing-Long,Liu, Fengting,Yousufuddin, Muhammed,Ess, Daniel H.,Kürti, László,Gao, Hongyin
, p. 7992 - 7999 (2018/11/03)
A transition metal-free dehydrogenative method for the direct mono-arylation of a wide range of activated C(sp3)-H bonds has been developed. This operationally simple and environmentally friendly aerobic arylation uses tert-BuOK as the base and nitroarenes as electrophiles to prepare up to gram quantities of structurally diverse sets (>60 examples) of α-arylated esters, amides, nitriles, sulfones and triaryl methanes. DFT calculations provided a predictive model, which states that substrates containing a C(sp3)-H bond with a sufficiently low pKa value should readily undergo arylation. The DFT prediction was confirmed through experimental testing of nearly a dozen substrates containing activated C(sp3)-H bonds. This arylation method was also used in a one-pot protocol to synthesize over twenty compounds containing all-carbon quaternary centers.
Photochemical intramolecular amination for the synthesis of heterocycles
Parisien-Collette, Shawn,Cruché, Corentin,Abel-Snape, Xavier,Collins, Shawn K.
, p. 4798 - 4803 (2017/10/23)
Polycyclic heterocycles can be formed in good to excellent yields via photochemical conversion of the corresponding substituted aryl azides under irradiation with purple LEDs in a continuous flow reactor. The experimental set-up is tolerant to UV-sensitive functional groups while affording diverse carbazoles, as well as an indole and pyrrole framework, in short reaction times. The photochemical method is presumed to progress through a mechanism differing from the other methods of azide activation involving transition metal catalysis.