1143018-79-4Relevant articles and documents
An Aluminum Hydride That Functions like a Transition-Metal Catalyst
Yang, Zhi,Zhong, Mingdong,Ma, Xiaoli,De, Susmita,Anusha, Chakkittakandiyil,Parameswaran, Pattiyil,Roesky, Herbert W.
, p. 10225 - 10229 (2015)
The reaction of [LAlH2] (L=HC(CMeNAr)2, Ar=2,6-iPr2C6H3) with MeOTf (Tf=SO2CF3) resulted in the formation of [LAlH(OTf)] (1) in high yield. The triflate substituent in 1 increases the positive charge at the aluminum center, which implies that 1 has a strong Lewis acidic character. The excellent catalytic activity of 1 for the hydroboration of organic compounds with carbonyl groups was investigated. Furthermore, it was shown that 1 effectively initiates the addition reaction of trimethylsilyl cyanide (TMSCN) to both aldehydes and ketones. Quantum mechanical calculations were carried out to explore the reaction mechanism.
Catalytic regeneration of a Th-H bond from a Th-O bond through a mild and chemoselective carbonyl hydroboration
Ghatak, Tapas,Makarov, Konstantin,Fridman, Natalia,Eisen, Moris S.
, p. 11001 - 11004 (2018)
Here we present an unprecedented chemoselective hydroboration for aldehydes and ketones catalysed by actinides. The reaction features a very low catalyst loading (0.1-0.004 mol%) and quantitative product formation in less than 15 minutes, at room temperature. Thermodynamic and kinetic studies including stoichiometric and labeling studies with deuterated pinacolborane allow us to propose a plausible mechanism for this remarkable catalytic regeneration of a Th-H bond via carbonyl hydroboration.
Arsenic Catalysis: Hydroboration of Aldehydes Using a Benzo-Fused Diaza-benzyloxy-arsole
Ould, Darren M. C.,Melen, Rebecca L.
, p. 15201 - 15204 (2018)
The first example of a homogenous AsIII catalyst for hydroboration has been established. The reaction of N,N′-diisopropylbenzene diamine or toluene-3,4-dithiol with AsCl3 yielded the chloroarsoles (1 and 2), which upon reaction with
Iron(II) hydrides bearing a tetradentate PSNP ligand
Liu, Jianguo,Zhang, Ailing,Song, Heng,Tong, Qingxiao,Tung, Chen-Ho,Wang, Wenguang
, p. 949 - 953 (2018)
A new class of iron(II) hydrides based on a tetradentate PSNP ligand were synthesized and fully characterized. All the iron(II) complexes feature a folded PSNP ligand with cis reactive sites. The hydrido iron complex [2H(NCMe)](BF4) is capable of catalyzing aldehyde hydroboration by pinacolborane (HBpin) and with extremely high efficiency at room temperature. Aldehydes with various functional groups are compatible.
N-Heterocyclic Germylene and Stannylene Catalyzed Cyanosilylation and Hydroboration of Aldehydes
Dasgupta, Rajarshi,Das, Shubhajit,Hiwase, Shweta,Pati, Swapan K.,Khan, Shabana
, p. 1429 - 1435 (2019)
Recent years have witnessed a significant growth in the area of low-valent main-group compounds due to their potential to activate small molecules. However, there is a paucity of examples of low-valent main-group compounds being used as single-site cataly
Efficient and Selective Iron-Complex-Catalyzed Hydroboration of Aldehydes
Das, Uttam K.,Higman, Carolyn S.,Gabidullin, Bulat,Hein, Jason E.,Tom Baker
, p. 1076 - 1081 (2018)
An imine-coupled [Fe-N2S2]2 complex, prepared from a readily available benzothiazolidine ligand, catalyzes selectively the hydroboration of aliphatic and aromatic aldehydes at low catalyst loadings (0.1 mol %) using pinaco
Synthesis and characterization of rare-earth metallate amido complexes bearing the 2-amidate-functionalized indolyl ligand and their application in the hydroboration of esters with pinacolborane
Bao, Qin,Gao, Jianjian,Hong, Dongjing,Mu, Xiaolong,Song, Lulu,Wang, Shaowu,Wei, Yun,Zhou, Shuangliu,Zhu, Xiancui
, p. 2953 - 2961 (2022/02/21)
The reactions of 2-amidate-functionalized indolyl proligand 2-(2,6-iPr2C6H3NHCO)C8H5NH (H2L) with [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 were studied leading to the synthesis and characterization of a series of novel discrete trinuclear rare-earth metallate amido complexes containing the anion [{η1:(μ2-η1:η1):η1-LREN(SiMe3)2}3(μ3-Cl)]? and cation Li+(THF)4 (RE = Y(1a), Nd (1b), Sm (1c), Gd (1d), Dy (1e), Er (1f), and Yb (1g)) in good yields by silylamine elimination. All of the complexes were characterized by spectroscopic methods, elemental analyses and single-crystal X-ray diffraction, and complexes 1a and 1c were additionally characterized by NMR spectroscopy. As proof of principle of their activity, these complexes were used as precatalysts for the hydroboration of esters using HBpin as the hydride source displaying high activity under neat and room temperature conditions. As a result, the ligand, ionic and multinuclear cooperative effects on catalytic activity were observed.
Hydroborative reduction of amides to amines mediated by La(CH2C6H4NMe2-: O)3
Gong, Mingliang,Guo, Chenjun,Luo, Yunjie,Xie, Hongzhen,Zhang, Fangcao
, p. 779 - 791 (2022/01/22)
The deoxygenative reduction of amides to amines is a great challenge for resonance-stabilized carboxamide moieties, although this synthetic strategy is an attractive approach to access the corresponding amines. La(CH2C6H4NMe2-o)3, a simple and easily accessible lanthanide complex, was found to be highly efficient not only for secondary and tertiary amide reduction, but also for the most challenging primary reduction with pinacolborane. This protocol exhibited good tolerance for many functional groups and heteroatoms, and could be applied to gram-scale synthesis. The active species in this catalytic cycle was likely a lanthanide hydride.
Catalytic Hydroboration of Esters by Versatile Thorium and Uranium Amide Complexes
Makarov, Konstantin,Kaushansky, Alexander,Eisen, Moris S.
, p. 273 - 284 (2022/01/03)
The challenging hydroboration of esters is achieved using simple uranium and thorium amides, U[N(SiMe3)2]3 and [(Me3Si)2N]2An[κ2-(N,C)-CH2Si(CH3)2N(SiMe3)] (An = Th or U) acting as precatalysts in the reaction with pinacolborane (HBpin). All three complexes showed impressive catalytic activities, reaching excellent yields. A large scope of esters was investigated including aliphatic, aromatic, and heterocyclic esters that were transformed cleanly to the corresponding hydroborated alcohols, which readily hydrolyzed to the free alcohols. Moreover, the actinide catalysts demonstrated unexpected high functional tolerance toward nitro, halide, cyano, and heteroaromatic functional groups. The reaction exhibited excellent selectivity toward the ester when additional double and triple unsaturated C-C bonds were present. Lactones and poly caprolactone have been successfully cleaved to the monomeric units, showing a great promise toward polymer degradation and recycling. Detailed kinetic studies are provided in order to determine the rate dependence on the concentration of catalyst, HBpin, and ester. A plausible mechanism is proposed based on stoichiometric reactions, DFT calculations, thermodynamic measurements, and deuterium-labeling studies.
Manganese-Catalyzed Hydroborations with Broad Scope
Ghosh, Pradip,Jacobi von Wangelin, Axel
supporting information, p. 16035 - 16043 (2021/06/16)
Reductive transformations of easily available oxidized matter are at the heart of synthetic manipulation and chemical valorization. The applications of catalytic hydrofunctionalization benefit from the use of liquid reducing agents and operationally facile setups. Metal-catalyzed hydroborations provide a highly prolific platform for reductive valorizations of stable C=X electrophiles. Here, we report an especially facile, broad-scope reduction of various functions including carbonyls, carboxylates, pyridines, carbodiimides, and carbonates under very mild conditions with the inexpensive pre-catalyst Mn(hmds)2. The reaction could be successfully applied to depolymerizations.
