6299-04-3Relevant academic research and scientific papers
Achieving Aliphatic Amine Addition to Arylalkynes via the Lewis Acid Assisted Triazole-Gold (TA-Au) Catalyst System
Jia, Teng,Fan, Shengyu,Li, Fengmian,Ye, Xiaohan,Zhang, Wenke,Song, Zhiguang,Shi, Xiaodong
supporting information, p. 6019 - 6023 (2021/08/03)
Transition metal catalyzed intermolecular hydroamination of the arylalkynes with aliphatic amine is generally problematic due to the good coordination between amine and metal cation. With the combination of 1,2,3-triazole coordinated gold(I) catalyst (TA-Au) and Zn(OTf)2 cocatalyst, this challenging transformation was achieved with good to excellent yields and regioselectivity. Compared to previously reported methods, this approach offered an alternative catalyst system to achieve this fundamental chemical transformation with high efficiency and practical conditions.
Cleavage∕cross-coupling strategy for converting β-O-4 linkage lignin model compounds into high valued benzyl amines via dual C–O bond cleavage
Jia, Le,Li, Chao-Jun,Zeng, Huiying
, (2021/10/29)
Lignin is the most recalcitrant of the three components of lignocellulosic biomass. The strength and stability of the linkages have long been a great challenge for the degradation and valorization of lignin biomass to obtain bio-fuels and commercial chemicals. Up to now, the selective cleavage of C–O linkages of lignin to afford chemicals contains only C, H and O atoms. Our group has developed a cleavage/cross-coupling strategy for converting 4-O-5 linkage lignin model compounds into high value-added compounds. Herein, we present a palladium-catalyzed cleavage/cross-coupling of the β-O-4 lignin model compounds with amines via dual C–O bond cleavage for the preparation of benzyl amine compounds and phenols.
Chan-Lam Amination of Secondary and Tertiary Benzylic Boronic Esters
Dennis, Francesca M.,Grayson, James D.,Partridge, Benjamin M.,Robertson, Craig C.
, p. 9883 - 9897 (2021/07/20)
We report a Chan-Lam coupling reaction of benzylic and allylic boronic esters with primary and secondary anilines to form valuable alkyl amine products. Both secondary and tertiary boronic esters can be used as coupling partners, with mono-alkylation of the aniline occurring selectively. This is a rare example of a transition-metal-mediated transformation of a tertiary alkylboron reagent. Initial investigation into the reaction mechanism suggests that transmetalation from B to Cu occurs through a single-electron, rather than a two-electron process.
Ligand-free Iron(II)-Catalyzed N-Alkylation of Hindered Secondary Arylamines with Non-activated Secondary and Primary Alcohols via a Carbocationic Pathway
Nayal, Onkar S.,Thakur, Maheshwar S.,Kumar, Manoranjan,Kumar, Neeraj,Maurya, Sushil K.
supporting information, p. 730 - 737 (2017/12/26)
Secondary benzylic alcohols represent a challenging class of substrates for N-alkylation of amines. Herein, we describe an iron(II)-catalyzed eco-friendly protocol for N-alkylation of secondary arylamines with secondary benzyl alcohols through a carbocationic pathway instead of the known borrowing hydrogen transfer (BHT) approach. Transiently generated carbocations, produced from alcohols via self-condensation, were coupled with arylamines to provide highly functionalized amine products. The scope of this methodology involves N-alkylation of primary, secondary and heterocyclic amines with primary/secondary benzylic, allylic and heterocyclic alcohols, which are common key structures in numerous pharmaceuticals drugs. The method can also be easily adopted for the amination of various natural products. (Figure presented.).
A Salan-shaped former transition metal amido and its preparation method and application
-
Paragraph 0069-0070, (2017/04/21)
The invention discloses Salan-type early transition metal amide and a preparation method and application thereof. The Salan-type early transition metal amide disclosed by the invention is characterized in that a general formula of the Salan-type early tra
Synthesis of tertiary arylamines: Lewis acid-catalyzed direct reductive: N -alkylation of secondary amines with ketones through an alternative pathway
Nayal, Onkar S.,Thakur, Maheshwar S.,Bhatt, Vinod,Kumar, Manoranjan,Kumar, Neeraj,Singh, Bikram,Sharma, Upendra
supporting information, p. 9648 - 9651 (2016/08/04)
We report herein a highly efficient, tin(ii)/PMHS catalyzed reductive N-alkylation of arylamines with ketones affording tertiary arylamines. A very wide substrate scope was observed for the current catalytic method as all six permutations of ketones/aldehydes/heterocyclic carbonyls and primary/secondary/heterocyclic amines were well tolerated, enabling access to secondary, tertiary and heterocyclic amines. The method is also convenient for the synthesis of N-substituted isoindolinones and phthalazinones via a tandem amination-amidation sequence. Mechanistic investigations revealed a carbocationic pathway instead of an ordinary direct reductive amination pathway.
Tin-Catalyzed Selective Reductive Hydroamination of Alkynes for the Synthesis of Tertiary Amines
Nayal, Onkar S.,Thakur, Maheshwar S.,Kumar, Manoranjan,Sharma, Sushila,Kumar, Neeraj
, p. 1103 - 1109 (2016/04/19)
A unique preference of tin(II) for aniline activation is disclosed. In the present work tin(II) triflate-catalyzed highly selective Markovnikov reductive hydroamination of internal as well as terminal alkynes is reported. The mechanistic study revealed the involvement of two steps in one pot wherein alkyne reduces to corresponding alkene in presence of PMHS as reducing agent followed by hydroamination of alkene. A broad range of alkynes transformed into tertiary amines with good to excellent yield. This method is equally applicable in synthesis of secondary amines.
Zirconium catalysed intermolecular hydroamination reactions of secondary amines with alkynes
Sun, Qiu,Wang, Yaorong,Yuan, Dan,Yao, Yingming,Shen, Qi
supporting information, p. 7633 - 7636 (2015/06/01)
An in situ generated cationic zirconium complex stabilized by an n-butylamine-bridged bis(phenolato) ligand has been developed to catalyse hydroamination reactions of secondary amines, which is the first example of group 4 metal based catalysts capable of
Ruthenium-catalyzed reductive methylation of imines using carbon dioxide and molecular hydrogen
Beydoun, Kassem,Ghattas, Ghazi,Thenert, Katharina,Klankermayer, Jürgen,Leitner, Walter
, p. 11010 - 11014 (2015/03/30)
The use of the well-defined [Ru(triphos)(tmm)] catalyst, CO2 as C1 source, and H2 as reducing agent enabled the reductive methylation of isolated imines, as well as the direct coupling of amines with aldehydes and the subsequent reductive methylation of the insitu formed imines. The method, which afforded the corresponding N-methyl amines in very good to excellent yields, was also used for the preparation of the antifungal agent butenafine in one step with no apparent waste, thus increasing the atom efficiency of its synthesis.
Br?nsted acid catalyzed monoalkylation of anilines with trichloroacetimidates
Wallach, Daniel R.,Stege, Patrick C.,Shah, Jigisha P.,Chisholm, John D.
, p. 1993 - 2000 (2015/02/19)
Trichloroacetimidates are useful alkylating agents for aromatic amines, requiring only a catalytic amount of a Br?nsted acid to facilitate the reaction. Monoalkylation predominates under these conditions. Electron-poor anilines provide superior yields, with electron-rich anilines sometimes showing competitive Friedel-Crafts alkylation. A single flask protocol with formation of the imidate in situ is demonstrated, providing a convenient method for the direct substitution of alcohols with anilines. Reaction with a chiral imidate favors a mechanism that proceeds through a carbocation intermediate.
