15258-46-5Relevant articles and documents
Pentacoordinated Carboxylate π-Allyl Nickel Complexes as Key Intermediates for the Ni-Catalyzed Direct Amination of Allylic Alcohols
Kita, Yusuke,Sakaguchi, Hironobu,Hoshimoto, Yoichi,Nakauchi, Daisuke,Nakahara, Yasuhito,Carpentier, Jean-Fran?ois,Ogoshi, Sensuke,Mashima, Kazushi
, p. 14571 - 14578 (2015)
Direct amination of allylic alcohols with primary and secondary amines catalyzed by a system made of [Ni(1,5-cyclooctadiene)2] and 1,1′-bis(diphenylphosphino)ferrocene was effectively enhanced by adding nBu4NOAc and molecular sieves, affording the corresponding allyl amines in high yield with high monoallylation selectivity for primary amines and high regioselectivity for monosubstituted allylic alcohols. Such remarkable additive effects of nBu4NOAc were elucidated by isolating and characterizing some nickel complexes, manifesting the key role of a charge neutral pentacoordinated η3-allyl acetate complex in the present system, in contrast to usual cationic tetracoordinated complexes earlier reported in allylic substitution reactions.
Synthesis of functionalized indoles via palladium-catalyzed cyclization of N-(2-allylphenyl) benzamide: A method for synthesis of indomethacin precursor
Chang, Zhe,Dong, Zheng,Ma, Tong,Zhang, Yu,Zhao, Depeng,Zhao, Heng
supporting information, (2020/03/19)
We developed an efficient method for synthesis of substituted N-benzoylindole via Pd(II)-catalyzed C-H functionalization of substituted N-(2-allylphenyl)benzamide. The reaction showed a broad substrate scope (including N-acetyl and N-Ts substrates) and substituted indoles were obtained in good to excellent yields. The most distinctive feature of this method lies in the high selectivity for N-benzoylindole over benzoxazine, and this is the first example of Pd(II)-catalyzed synthesis of substituted N-benzoylindole. Notably, this new method was applied for the synthesis of key intermediate of indomethacin.
Room Temperature Iron-Catalyzed Transfer Hydrogenation and Regioselective Deuteration of Carbon-Carbon Double Bonds
Espinal-Viguri, Maialen,Neale, Samuel E.,Coles, Nathan T.,MacGregor, Stuart A.,Webster, Ruth L.
supporting information, p. 572 - 582 (2019/01/08)
An iron catalyst has been developed for the transfer hydrogenation of carbon-carbon multiple bonds. Using a well-defined β-diketiminate iron(II) precatalyst, a sacrificial amine and a borane, even simple, unactivated alkenes such as 1-hexene undergo hydrogenation within 1 h at room temperature. Tuning the reagent stoichiometry allows for semi- and complete hydrogenation of terminal alkynes. It is also possible to hydrogenate aminoalkenes and aminoalkynes without poisoning the catalyst through competitive amine ligation. Furthermore, by exploiting the separate protic and hydridic nature of the reagents, it is possible to regioselectively prepare monoisotopically labeled products. DFT calculations define a mechanism for the transfer hydrogenation of propene with nBuNH2 and HBpin that involves the initial formation of an iron(II)-hydride active species, 1,2-insertion of propene, and rate-limiting protonolysis of the resultant alkyl by the amine N-H bond. This mechanism is fully consistent with the selective deuteration studies, although the calculations also highlight alkene hydroboration and amine-borane dehydrocoupling as competitive processes. This was resolved by reassessing the nature of the active transfer hydrogenation agent: experimentally, a gel is observed in catalysis, and calculations suggest this can be formulated as an oligomeric species comprising H-bonded amine-borane adducts. Gel formation serves to reduce the effective concentrations of free HBpin and nBuNH2 and so disfavors both hydroboration and dehydrocoupling while allowing alkene migratory insertion (and hence transfer hydrogenation) to dominate.
