4160-52-5Relevant articles and documents
Rh-Catalyzed Coupling of Aldehydes with Allylboronates Enables Facile Access to Ketones
Zhang, Kezhuo,Huang, Jiaxin,Zhao, Wanxiang
supporting information, (2022/02/21)
We present herein a novel strategy for the preparation of ketones from aldehydes and allylic boronic esters. This reaction involves the allylation of aldehydes with allylic boronic esters and the Rh-catalyzed chain-walking of homoallylic alcohols. The key to this successful development is the protodeboronation of alkenyl borylether intermediate via a tetravalent borate anion species in the presence of KHF2 and MeOH. This approach features mild reaction conditions, broad substrate scope, and excellent functional group tolerance. Mechanistic studies also supported that the tandem allylation and chain-walking process were involved.
Iridium-Catalyzed Asymmetric Hydrogenation of α-Fluoro Ketones via a Dynamic Kinetic Resolution Strategy
Tan, Xuefeng,Wen, Jialin,Zeng, Weijun,Zhang, Xumu
supporting information, p. 7230 - 7233 (2020/10/02)
The discrimination of a fluorine atom from a hydrogen atom has been challenging in asymmetric catalysis. We herein report iridium-catalyzed hydrogenation of α-fluoro ketones using a strategy of dynamic kinetic resolution. Both enantiomeric and diastereomeric selectivities were satisfactory in the preparation of β-fluoro alcohols. The DFT calculation revealed a C-F···Na charge-dipole interaction in the transition state of hydride transfer. This noncovalent interaction would be responsible for the diastereomeric control.
Additive-Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst
Spiegelberg, Brian,Dell'Acqua, Andrea,Xia, Tian,Spannenberg, Anke,Tin, Sergey,Hinze, Sandra,de Vries, Johannes G.
supporting information, p. 7820 - 7825 (2019/05/22)
Catalytic isomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base increases the speed of the reaction drastically. Although some evidence was obtained supporting a dehydrogenation–hydrogenation mechanism, it was proven that this is not the major mechanism. Instead, the cobalt hydride complex formed by dehydrogenation of ethanol is capable of double-bond isomerization through alkene insertion–elimination.
