10436-75-6Relevant academic research and scientific papers
Selective Pd-catalyzed monoarylation of small primary alkyl amines through backbone-modification in ylide-functionalized phosphines (YPhos)
Rodstein, Ilja,Prendes, Daniel Sowa,Wickert, Leon,Paa?en, Maurice,Gessner, Viktoria H.
, p. 14674 - 14683 (2020/12/29)
Ylide-substituted phosphines have been shown to be excellent ligands for C-N coupling reactions under mild reaction conditions. Here we report studies on the impact of the steric demand of the substituent in the ylide-backbone on the catalytic activity. Two new YPhos ligands with bulky ortho-tolyl (pinkYPhos) and mesityl (mesYPhos) substituents were synthesized, which are slightly more sterically demanding than their phenyl analogue but considerably less flexible. This change in the ligand design leads to higher selectivities and yields in the arylation of small primary amines compared to previously reported YPhos ligands. Even MeNH2 and EtNH2 could be coupled at room temperature with a series of aryl chlorides in high yields.
Palladium Complexes Based on Ylide-Functionalized Phosphines (YPhos): Broadly Applicable High-Performance Precatalysts for the Amination of Aryl Halides at Room Temperature
Tappen, Jens,Rodstein, Ilja,McGuire, Katie,Gro?johann, Angela,L?ffler, Julian,Scherpf, Thorsten,Gessner, Viktoria H.
supporting information, p. 4281 - 4288 (2020/03/13)
Palladium allyl, cinnamyl, and indenyl complexes with the ylide-substituted phosphines Cy3P+?C?(R)PCy2 (with R=Me (L1) or Ph (L2)) and Cy3P+?C?(Me)PtBu2 (L3) were prepared and applied as defined precatalysts in C?N coupling reactions. The complexes are highly active in the amination of 4-chlorotoluene with a series of different amines. Higher yields were observed with the precatalysts in comparison to the in situ generated catalysts. Changes in the ligand structures allowed for improved selectivities by shutting down β-hydride elimination or diarylation reactions. Particularly, the complexes based on L2 (joYPhos) revealed to be universal precatalysts for various amines and aryl halides. Full conversions to the desired products are reached mostly within 1 h reaction time at room temperature, thus making L2 to one of the most efficient ligands in C?N coupling reactions. The applicability of the catalysts was demonstrated for aryl chlorides, bromides and iodides together with primary and secondary aryl and alkyl amines, including gram-scale applications also with low catalyst loadings of down to 0.05 mol %. Kinetic studies further demonstrated the outstanding activity of the precatalysts with TOF over 10.000 h?1.
A Highly Active Ylide-Functionalized Phosphine for Palladium-Catalyzed Aminations of Aryl Chlorides
Weber, Philip,Scherpf, Thorsten,Rodstein, Ilja,Lichte, Dominik,Scharf, Lennart T.,Goo?en, Lukas J.,Gessner, Viktoria H.
supporting information, p. 3203 - 3207 (2019/01/09)
Ylide-functionalized phosphine ligands (YPhos) were rationally designed to fit the requirements of Buchwald–Hartwig aminations at room temperature. This ligand class combines a strong electron-donating ability comparable to NHC ligands with high steric demand similar to biaryl phosphines. The active Pd species are stabilized by agostic C?H???Pd rather than by Pd–arene interactions. The practical advantage of YPhos ligands arises from their easy and scalable synthesis from widely available, inexpensive starting materials. Benchmark studies showed that YPhos-Pd complexes are superior to the best-known phosphine ligands in room-temperature aminations of aryl chlorides. The utility of the catalysts was demonstrated by the synthesis of various arylamines in high yields within short reaction times.
Cs2CO3-Promoted Direct N-Alkylation: Highly Chemoselective Synthesis of N-Alkylated Benzylamines and Anilines
Castillo, Juan-Carlos,Orrego-Hernández, Jessica,Portilla, Jaime
, p. 3824 - 3835 (2016/08/20)
Herein is described an efficient and chemoselective method for the synthesis of diversely substituted secondary amines in yields up to 98 %. Direct mono-N-alkylation of primary benzylamines and anilines with a wide range of alkyl halides is promoted by a cesium base in the absence of any additive or catalyst. The basicity and solubility of cesium carbonate in anhydrous N,N-dimethylformamide not only enables mono-N-alkylation of primary amines but also suppresses undesired dialkylation of the desired amines.
Nickel(II) complex covalently anchored on core shell structured SiO2@Fe3O4 nanoparticles: A robust and magnetically retrievable catalyst for direct one-pot reductive amination of ketones
Sharma, Rakesh Kumar,Dutta, Sriparna,Sharma, Shivani
, p. 2089 - 2101 (2016/03/19)
A robust and efficient core shell structured magnetically retrievable nickel nanocatalytic system was fabricated via the covalent immobilization of 2-acetyl furan on the surface of an amine functionalized silica coated magnetic nanosupport followed by its metallation with nickel acetate. The newly synthesized magnetic silica based organic-inorganic hybrid nanocatalyst (Ni-ACF@Am-SiO2@Fe3O4) was systematically affirmed using several physico-chemical characterization tools such as FT-IR, XRD, VSM, SEM, TEM, EDS, ED-XRF and AAS. Thereafter, the catalytic performance of this Ni-ACF@Am-SiO2@Fe3O4 nanocatalyst was investigated in the one-pot reductive amination of ketones using NaBH4 as the reductant under neat conditions. The developed core shell magnetic silica based nickel nanocatalyst successfully afforded a structurally diverse range of secondary amines with high turnover frequency (TOF) and excellent conversion percentage. Additionally, it was found that this catalyst could not only be retrieved from the reaction vessel within a fraction of seconds using an external magnet but also be recycled for multiple runs without any discernible loss in its activity that rendered this protocol superior to all the previously established methodologies for the one-pot synthesis of substituted amines. Besides, some of the other fascinating features of this methodology that made it a potential candidate for addressing various economic and environmental concerns were ambient reaction conditions, broad substrate scope, simple workup procedure, shorter reaction time and cost effectiveness.
Alkylation of Amines with Alcohols and Amines by a Single Catalyst under Mild Conditions
Zou, Qingzhu,Wang, Chao,Smith, Jen,Xue, Dong,Xiao, Jianliang
supporting information, p. 9656 - 9661 (2015/06/30)
An efficient catalytic system for the alkylation of amines with either alcohols or amines under mild conditions has been developed, using cyclometallated iridium complexes as catalysts. The method has broad substrate scope, allowing for the synthesis of a diverse range of secondary and tertiary amines with good to excellent yields. By controlling the ratio of substrates, both mono- and bis-alkylated amines can be obtained with high selectivity. In particular, methanol can be used as the alkylating reagent, affording N-methylated products selectively. A strong solvent effect is observed for the reaction.
Synthesis, reactivities, and catalytic properties of iodo-bridged polymeric iridium complexes with flexible carbon chain-bridged bis(tetramethylcyclopentadienyl) ligands
Tan, Xing,Li, Bin,Xu, Shansheng,Song, Haibin,Wang, Baiquan
, p. 3253 - 3261 (2013/07/19)
Dinuclear iridium complexes [(C5Me4)(CH 2)n(C5Me4)][Ir(COD)]2 (2a: n = 2; 2b: n = 3; 2c: n = 4) are obtained from the reactions of the corresponding dilithium salts Li2/sub
Development of a general non-noble metal catalyst for the benign amination of alcohols with amines and ammonia
Cui, Xinjiang,Dai, Xingchao,Deng, Youquan,Shi, Feng
supporting information, p. 3665 - 3675 (2013/03/29)
The N-alkylation of amines or ammonia with alcohols is a valuable route for the synthesis of N-alkyl amines. However, as a potentially clean and economic choice for N-alkyl amine synthesis, non-noble metal catalysts with high activity and good selectivity are rarely reported. Normally, they are severely limited due to low activity and poor generality. Herein, a simple NiCuFeOx catalyst was designed and prepared for the N-alkylation of ammonia or amines with alcohol or primary amines. N-alkyl amines with various structures were successfully synthesized in moderate to excellent yields in the absence of organic ligands and bases. Typically, primary amines could be efficiently transformed into secondary amines and N-heterocyclic compounds, and secondary amines could be N-alkylated to synthesize tertiary amines. Note that primary and secondary amines could be produced through a one-pot reaction of ammonia and alcohols. In addition to excellent catalytic performance, the catalyst itself possesses outstanding superiority, that is, it is air and moisture stable. Moreover, the magnetic property of this catalyst makes it easily separable from the reaction mixture and it could be recovered and reused for several runs without obvious deactivation. Copyright
Palladium-catalyzed aerobic dehydrogenative aromatization of cyclohexanone imines to arylamines
Hajra, Alakananda,Wei, Ye,Yoshikai, Naohiko
supporting information, p. 5488 - 5491,4 (2012/12/12)
Dehydrogenative aromatization of cyclohexanone imines to arylamines has been achieved using a palladium catalyst under aerobic conditions. The reaction is applicable to a variety of imines that are either preformed or generated in situ from cyclohexanone derivatives and aryl or alkylamines.
Tertiary alcohols by tandem β-carbolithiation and N→C aryl migration in enol carbamates
Fournier, Anne M.,Clayden, Jonathan
supporting information; experimental part, p. 142 - 145 (2012/02/14)
Enol carbamates (O-vinylcarbamates) derived from aromatic or α,β-unsaturated compounds and bearing an N-aryl substituent undergo carbolithiation by nucleophilic attack at the (nominally nucleophilic) β position of the enol double bond. The resulting carbamate-stabilized allylic, propargylic, or benzylic organolithium rearranges with N→C migration of the N-aryl substituent, creating a quaternary carbon α to O. The products may be readily hydrolyzed to yield multiply branched tertiary alcohols in a one-pot tandem reaction, effectively a polarity-reversed nucleophilic β-alkylation-electrophilic α-arylation of an enol equivalent.
