5625-90-1Relevant articles and documents
N-Heterocyclic Carbene-Stabilized Germa-acylium Ion: Reactivity and Utility in Catalytic CO2Functionalizations
Sarkar, Debotra,Weetman, Catherine,Dutta, Sayan,Schubert, Emeric,Jandl, Christian,Koley, Debasis,Inoue, Shigeyoshi
supporting information, p. 15403 - 15411 (2020/10/20)
The first acceptor-free heavier germanium analogue of an acylium ion, [RGe(O)(NHC)2]X (R = MesTer = 2,6-(2,4,6-Me3C6H2)2C6H3; NHC = IMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene; X = (Cl or BArF = {(3,5-(CF3)2C6H5)4B}), was isolated by reacting [RGe(NHC)2]X with N2O. Conversion of the germa-acylium ion to the first solely donor-stabilized germanium ester [(NHC)RGe(O)(OSiPh3)] and corresponding heavier analogues ([RGe(S)(NHC)2]X and [RGe(Se)(NHC)2]X) demonstrated its classical acylium-like behavior. The polarized terminal GeO bond in the germa-acylium ion was utilized to activate CO2 and silane, with the former found to be an example of reversible activation of CO2, thus mimicking the behavior of transition metal oxides. Furthermore, its transition-metal-like nature is demonstrated as it was found to be an active catalyst in both CO2 hydrosilylation and reductive N-functionalization of amines using CO2 as the C1 source. Mechanistic studies were undertaken both experimentally and computationally, which revealed that the reaction proceeds via an N-heterocyclic carbene (NHC) siloxygermylene [(NHC)RGe(OSiHPh2)].
Supported nano-gold-catalyzed N-formylation of amines with paraformaldehyde in water under ambient conditions
Ke, Zhengang,Zhang, Yan,Cui, Xinjiang,Shi, Feng
, p. 808 - 816 (2016/02/12)
A simple and efficient Au/Al2O3 catalyst was prepared by the co-precipitation method for the oxidative N-formylation of amines with paraformaldehyde. Under the optimized reaction conditions, excellent amine conversion and N-formamide selectivity can be obtained with up to 97% yield with water as the solvent under ambient conditions. This catalyst tolerated a wide range of primary amines and second amines, and it can be reused for at least five runs without obvious deactivation.
(E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation
Shi, Renyi,Zhang, Hua,Lu, Lijun,Gan, Pei,Sha, Yuchen,Zhang, Heng,Liu, Qiang,Beller, Matthias,Lei, Aiwen
supporting information, p. 3247 - 3250 (2015/06/16)
A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO. This journal is