- Selective Pd-catalyzed monoarylation of small primary alkyl amines through backbone-modification in ylide-functionalized phosphines (YPhos)
-
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.
- Rodstein, Ilja,Prendes, Daniel Sowa,Wickert, Leon,Paa?en, Maurice,Gessner, Viktoria H.
-
p. 14674 - 14683
(2020/12/29)
-
- Palladium Complexes Based on Ylide-Functionalized Phosphines (YPhos): Broadly Applicable High-Performance Precatalysts for the Amination of Aryl Halides at Room Temperature
-
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.
- 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)
-
- A Highly Active Ylide-Functionalized Phosphine for Palladium-Catalyzed Aminations of Aryl Chlorides
-
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.
- 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)
-
- 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
-
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.
- Sharma, Rakesh Kumar,Dutta, Sriparna,Sharma, Shivani
-
p. 2089 - 2101
(2016/03/19)
-
- Cs2CO3-Promoted Direct N-Alkylation: Highly Chemoselective Synthesis of N-Alkylated Benzylamines and Anilines
-
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.
- Castillo, Juan-Carlos,Orrego-Hernández, Jessica,Portilla, Jaime
-
p. 3824 - 3835
(2016/08/20)
-
- Alkylation of Amines with Alcohols and Amines by a Single Catalyst under Mild Conditions
-
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.
- Zou, Qingzhu,Wang, Chao,Smith, Jen,Xue, Dong,Xiao, Jianliang
-
supporting information
p. 9656 - 9661
(2015/06/30)
-
- Synthesis, reactivities, and catalytic properties of iodo-bridged polymeric iridium complexes with flexible carbon chain-bridged bis(tetramethylcyclopentadienyl) ligands
-
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
- Tan, Xing,Li, Bin,Xu, Shansheng,Song, Haibin,Wang, Baiquan
-
p. 3253 - 3261
(2013/07/19)
-
- Development of a general non-noble metal catalyst for the benign amination of alcohols with amines and ammonia
-
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
- Cui, Xinjiang,Dai, Xingchao,Deng, Youquan,Shi, Feng
-
supporting information
p. 3665 - 3675
(2013/03/29)
-
- Tertiary alcohols by tandem β-carbolithiation and N→C aryl migration in enol carbamates
-
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.
- Fournier, Anne M.,Clayden, Jonathan
-
supporting information; experimental part
p. 142 - 145
(2012/02/14)
-
- Palladium-catalyzed aerobic dehydrogenative aromatization of cyclohexanone imines to arylamines
-
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.
- Hajra, Alakananda,Wei, Ye,Yoshikai, Naohiko
-
supporting information
p. 5488 - 5491,4
(2012/12/12)
-
- Zinc-promoted, iridium catalyzed reductive alkylation of primary amines with aliphatic ketones in aqueous medium
-
The reductive alkylation of primary aromatic and aliphatic amines with aliphatic ketones has been achieved in aqueous acidic medium using commercially available, non-activated zinc dust catalyzed by a very small quantity of iridium bromide. Anilines react well in aqueous formic acid, whereas monoalkylamines require 1,4-dioxane as a co-solvent and sulfuric acid as the proton source. A plausible mechanism via low-valent iridium hydride species is proposed.
- da Silva, Renato A.,Bieber, Lothar W.
-
scheme or table
p. 689 - 691
(2010/04/02)
-
- Sulfonato-Cu(salen) complex catalyzed N-arylation of aliphatic amines with aryl halides in water
-
A water-soluble sulfonato-Cu(salen) complex catalyzed procedure for the N-arylation of simple aliphatic amines, amino alcohols and amino acids in pure water have been developed. A variety of substituted aryl iodides, bromides and electron-deficient chlorides were found to be applicable, and 1,2-disubstituted benzimidazoles could be prepared easily by a cascade amination/condensation process in this catalytic system.
- Wu, Zhiqing,Zhou, Li,Jiang, Zhaoqiong,Wu, Di,Li, Zhengkai,Zhou, Xiangge
-
experimental part
p. 4971 - 4975
(2010/11/03)
-
- Cyclic triolborates: Air- and water-stable ate complexes of organoboronic acids
-
(Chemical Equation Presented) A borate in the hand is a convenient reagent for palladium- and copper-catalyzed C-C and C-N bond-forming reactions, especially when, like the title bench-stable complexes, it demonstrates high transmetalation efficiency. Cyclic triolborates can be synthesized readily from organoboronic acids (see scheme), can be handled and stored without special precautions, and are relatively soluble in organic solvents.
- Yamamoto, Yasunori,Takizawa, Miho,Yu, Xiao-Qiang,Miyaura, Norio
-
p. 928 - 931
(2008/09/20)
-
- A reductive amination of carbonyls with amines using decaborane in methanol
-
Aldehydes and ketones were easily converted to the corresponding amines by the reaction of amines in methanol using decaborane (B10H14) at room temperature under nitrogen. The reaction is simple and efficient. The Royal Society of Chemistry 2000.
- Bae, Jong Woo,Lee, Seung Hwan,Cho, Young Jin,Yoon, Cheol Min
-
p. 145 - 146
(2007/10/03)
-
- CCK or gastrin modulating benzo ?b!?1,4! diazepines derivatives
-
Benzo?b!?1,4!diazepine compounds of formula (I), where R1 is selected from C1 C6 alkyl, C3 -C6 cycloalkyl, phenyl, or substituted phenyl; R2 is selected from C3 -C6 alkyl, C3 C6 cycloalkyl, C3 -C6 alkenyl, benzyl, phenylC1 -C3 alkyl of substituted phenyl; or NR1 R2 together form 1,2,3,4-tetrahydroquinoline or benzazepine, mono-, di-, or trisubstituted independently with C1-6 alkyl C1-6 alkoxy or halogen substituents; p is an integer 0 or 1; q is an integer 0 or 1; r is an integer 0 or 1; t is an integer 0 or 1, provided that when r is 0 then t is 0; R3, R5, and R6 are independently hydrogen or C1-6 alkyl; R4 is C1-6 alkyl or C1-6 alkenyl; R7 is selected from the group consisting of hydrogen, C1-6 alkyl, C1-6 cycloalkyl, C1-6 alkenyl, phenyl, substituted phenyl, napthyl, heteroaryl, substituted heteroaryl, bicycloheteroaryl or substituted bicycloheteroaryl; or NR6 R7 together form a saturated 5,6, or 7 membered ring optionally interrupted by 1,2,3 or 4 N, S or O heteroatoms, with the proviso that any two O or S atoms are not bonded to each other, m is an integer selected from the group of 0, 1, 2, 3 or 4; R8 and R9 are selected from a variety of substituents; Z is hydrogen or halogen; novel intermediates, a pharmaceutical composition for treating obesity, gall bladder stasis, disorders of pancreatic secretion, methods for such treatment and processes for preparing compounds of formula (I).
- -
-
-
- USE OF HEXAMETHYLPHOSPHORAMIDE (HMPA) IN THE ALKYLATION OF AROMATIC AMINES
-
The convenience of using HMPA as solvent in the mono and dialkylation of anilines was demonstrated through the study of the reaction of p-toluidine with alkyl halides, tosylates and epoxides.
- Juaristi, Eusebio,Reyna, J. Daniel
-
p. 3521 - 3524
(2007/10/02)
-
- ALCOHOLS AND ALUMINIUM ALKOXIDES IN THE PRESENCE OF RANEY-NICKEL AS ALKYLATING AGENTS. II. A KINETIC STUDY OF ALKYLATION OF AROMATIC AMINES
-
The kinetics of N-alkylation of substituted anilines with isopropanol and aluminium isopropoxide, catalysed by Raney-nickel, have been studied.The reaction proceeds according to a second-order equation.The formation of the Schiff's bases of the anilines along the reaction courses have been detected.The data reported also show that the reaction rates depend upon the nucleophilicity of the substrate to be alkylated.A possible mechanism is discussed.
- Angelis, Francesco De,Ferretti, Gabriella,Botta, Maurizio,Grgurina, Ingeborg,Nicoletti, Rosario
-
p. 267 - 272
(2007/10/02)
-