103-83-3Relevant articles and documents
B(C6F5)3-catalyzed methylation of amines using CO2 as a C1 building block
Yang, Zhenzhen,Yu, Bo,Zhang, Hongye,Zhao, Yanfei,Ji, Guipeng,Ma, Zhishuang,Gao, Xiang,Liu, Zhimin
, p. 4189 - 4193 (2015)
B(C6F5)3 was proven to be an efficient metal-free catalyst for the methylation of amines using CO2 as a C1 building block in the presence of hydrosilanes under easy-handling conditions. A broad range of N-alkylanilines, dialkylamines and primary anilines all proceeded well under the catalytic conditions.
Bis- n -heterocyclic carbene (nhc) stabilized η6-arene iron(0) complexes: Synthesis, structure, reactivity, and catalytic activity
Blom, Burgert,Tan, Gengwen,Enthaler, Stephan,Inoue, Shigeyoshi,Epping, Jan Dirk,Driess, Matthias
, p. 18108 - 18120 (2013)
Reaction of FeCl2 with the chelating bis-N-heterocyclic carbene (NHC) bis-(N-Dipp-imidazole-2-ylidene)methylene (abbreviated {( DippC:)2CH2}) (Dipp = 2,6-di-isopropylphenyl) affords the complex [FeCl2{(DippC:)2CH 2}] (1) in high yield. Reduction of complex 1 with excess KC 8 with a 10-fold molar excess of PMe3 affords the Fe(II) complex [FeH{(DippC:)2CH2}(PMe 3)(η2-PMe2CH2)] (2) as a mixture of three stereoisomers. Complex 2, the first example of any iron(II) complex bearing mutually an NHC and PMe3 ligand, is likely obtained from the in situ, reductively generated 16 VE Fe(0) complex, [Fe{(DippC:) 2CH2}(PMe3)2] (2′), following intramolecular C-H activation of one of the phosphorus-bound CH3 groups. Complex 2 is unstable in aromatic solvents and forms, via a novel synthetic transformation involving intramolecular reductive elimination and concomitant PMe3 elimination, the Fe (0) arene complex [Fe{( DippC:)2CH2}(η6-C 6D6)] (4-d6) in C6D6. Complex 4-d6 represents the first example of an NHC stabilized iron (0) arene complex. The transformation from 2 to 4-d6 can be accelerated at higher temperature and at 60 C forms immediately. Alternatively, the reduction of 1 in the presence of toluene or benzene affords the complexes [Fe{(DippC:)2CH2}(η6-C 7H8)] (3) and [Fe{(DippC:)2CH 2}(η6-C6H6)] (4), selectively and in good yields. DFT calculations characterizing the bonding situation in 3 and 4 reveal similar energies of the HOMO and LUMO orbitals, with the LUMO orbital of both complexes located on the Dipp rings of the bis-NHC. The HOMO orbital reflects a π-back-bonding interaction between the Fe(0) center and the chelating NHC ligand, while the HOMO-1 is associated with the arene interaction with the Fe(0) site. The calculations do not suggest any noninnocence of the coordinated arene in either complex. Moreover, the 57Fe Moessbauer spectrum of 4 at 80K exhibits parameters (δ = 0.43 mm·s-1; ΔEQ = 1.37 mm·s -1) which are consistent with a five-coordinate Fe(0) system, rendering 3 and 4 the first examples of well-defined authentic Fe(0)-η6-arene complexes of the type [Fe(η6-arene) L2] (L = η1 or 2 neutral ligand, mono or bidentate). Some reactivitiy studies of 3 are also reported: The reaction of 3 with excess CO selectively yields the five-coordinate piano-stool complex [Fe{( DippC:)2CH2}(CO)3] (6) in near quantitative yields, while the reaction of complex 3 with C6D 6 under heating affords by toluene elimination 4-d6. The catalytic ability of 4 was also investigated with respect to amide reduction to amines, for a variety of substrates using Ph2SiH2 as a hydride source. In all cases good to excellent yields to the corresponding amines were obtained. The use of 4 as a precatalyst represents the first example of a well-defined Fe(0) complex to effect this catalytic process.
Metalated Mesoporous Poly(triphenylphosphine) with Azo Functionality: Efficient Catalysts for CO2 Conversion
Yang, Zhenzhen,Yu, Bo,Zhang, Hongye,Zhao, Yanfei,Chen, Yu,Ma, Zhishuang,Ji, Guipeng,Gao, Xiang,Han, Buxing,Liu, Zhimin
, p. 1268 - 1273 (2016)
Mesoporous poly(triphenylphosphine) with azo functionality (poly(PPh3)-azo) is reported, which was synthesized via oxidative polymerization of P(m-NH2Ph)3 at ambient conditions. This kind of polymer could strongly coordinate with metal ions (e.g., Ru3+) and could reduce Ag+ in situ to metallic form. The resultant metalated poly(PPh3)-azo (e.g., poly(PPh3)-azo-Ag or -Ru) were discovered to be highly efficient catalysts for CO2 transformation. Poly(PPh3)-azo-Ag showed more than 400 times higher site-time-yield (STY) for the carboxylative cyclization of propargylic alcohols with CO2 at room temperature compared with the best heterogeneous catalyst reported. Poly(PPh3)-azo-Ru also exhibited good activity for the methylation of amines with CO2. It was demonstrated that the high performances of the catalysts originated from the cooperative effects between the polymer and the metal species. In addition, both catalysts showed good stability and easy recyclability, thus demonstrating promising potential for practical utilization for the conversion of CO2 into value-added chemicals.
Photochemical Activation of Tertiary Amines for Applications in Studying Cell Physiology
Asad, Naeem,Deodato, Davide,Lan, Xin,Widegren, Magnus B.,Phillips, David Lee,Du, Lili,Dore, Timothy M.
, p. 12591 - 12600 (2017)
Representative tertiary amines were linked to the 8-cyano-7-hydroxyquinolinyl (CyHQ) photoremovable protecting group (PPG) to create photoactivatable forms suitable for use in studying cell physiology. The photoactivation of tamoxifen and 4-hydroxytamoxifen, which can be used to activate Cre recombinase and CRISPR-Cas9 gene editing, demonstrated that highly efficient release of bioactive molecules could be achieved through one- and two-photon excitation (1PE and 2PE). CyHQ-protected anilines underwent a photoaza-Claisen rearrangement instead of releasing amines. Time-resolved spectroscopic studies revealed that photorelease of the tertiary amines was extremely fast, occurring from a singlet excited state of CyHQ on the 70 ps time scale.
Reaction of alkyl sulfoxides and phenylphosphinic acid with amines. Alternative reagents for secondary amines N-alkylation
Chauvin
, p. 1425 - 1428 (1991)
Phenylphosphinic acid and dialkylsulfoxides are found to be alternative reagents for respectively the reducing reagent (formic acid) and the alkylating reagent (aldehyde) currently used for secondary amines N-alkylation. Primary amines do not react with this system, but phenylglycine is decarboxilated to benzylamine.
Borinic Acid Catalysed Reduction of Tertiary Amides with Hydrosilanes: A Mild and Chemoselective Synthesis of Amines
Chardon, Aurélien,Mohy El Dine, Tharwat,Legay, Rémi,De Paolis, Micha?l,Rouden, Jacques,Blanchet, Jér?me
, p. 2005 - 2009 (2017)
A reduction of various aryl, alkyl, and α,β-unsaturated amides with phenylsilane, catalysed by a borinic acid, is reported. The unprecedented reaction was carried out under very mild conditions and led to useful amines. Furthermore, the reaction tolerates a variety of functional groups. Initial investigations implicated that an intermediate diarylhydroborane is involved in the reaction mechanism.
Chemoselective Reduction of Tertiary Amides to Amines Catalyzed by Triphenylborane
Mukherjee, Debabrata,Shirase, Satoru,Mashima, Kazushi,Okuda, Jun
, p. 13326 - 13329 (2016)
Triphenylborane (BPh3) was found to catalyze the reduction of tertiary amides with hydrosilanes to give amines under mild condition with high chemoselectivity in the presence of ketones, esters, and imines. N,N-Dimethylacrylamide was reduced to provide the α-silyl amide. Preliminary studies indicate that the hydrosilylation catalyzed by BPh3may be mechanistically different from that catalyzed by the more electrophilic B(C6F5)3.
Base-promoted elimination reactions of acetaldehyde N-alkyl-N,N-dimethylhydrazonium salts. A convenient synthesis of N,N-dimethylalkylamines
Smith,Marcucci,Tingue
, p. 381 - 389 (1992)
The title reaction was utilized for efficient conversion of S(N)2-reactive alkyl halides to the corresponding N,N-dimethylalkylamines.
Efficient and Selective N-Methylation of Nitroarenes under Mild Reaction Conditions
Pedrajas, Elena,Sorribes, Iván,Guillamón, Eva,Junge, Kathrin,Beller, Matthias,Llusar, Rosa
, p. 13205 - 13212 (2017)
Herein, we report a straightforward protocol for the preparation of N,N-dimethylated amines from readily available nitro starting materials using formic acid as a renewable C1 source and silanes as reducing agents. This tandem process is efficiently accomplished in the presence of a cubane-type Mo3PtS4 catalyst. For the preparation of the novel [Mo3Pt(PPh3)S4Cl3(dmen)3]+ (3+) (dmen: N,N′-dimethylethylenediamine) compound we have followed a [3+1] building block strategy starting from the trinuclear [Mo3S4Cl3(dmen)3]+ (1+) and Pt(PPh3)4 (2) complexes. The heterobimetallic 3+ cation preserves the main structural features of its 1+ cluster precursor. Interestingly, this catalytic protocol operates at room temperature with high chemoselectivity when the 3+ catalyst co-exists with its trinuclear 1+ precursor. N-heterocyclic arenes, double bonds, ketones, cyanides and ester functional groups are well retained after N-methylation of the corresponding functionalized nitroarenes. In addition, benzylic-type as well as aliphatic nitro compounds can also be methylated following this protocol.
Base-Catalyzed Hydrosilylation of Nitriles to Amines and Esters to Alcohols
Clarke, Joshua A.,Nikonov, Georgii I.,van der Est, Art
, p. 4434 - 4439 (2021)
Base-catalyzed hydrosilylation of nitriles to amines and esters to silylated alcohols is reported. This protocol tolerates electron-rich and electron-neutral olefins and works in the presence of basic functional groups (e. g. tertiary amines) but fails for acidic substrates, such as phenols and NH anilines. This catalytic system does not tolerate carbonyl groups, such as aldehydes, ketones, esters and carbamides, which are reduced to corresponding alcohols and amines. With the exact amount of silane, esters can be selectively reduced in the presence of nitriles, but the selectivity drops for the pairs ester/carboxamide and carboxamide/nitrile. Through competition experiments, the following preference in functional group reactivity was determined: ester > carboxamide > nitrile.
