777-38-8Relevant articles and documents
Atomic Pt-Catalyzed Heterogeneous Anti-Markovnikov C-N Formation: Pt10Activating N-H for Pt1δ+-Activated C-C Attack
Ma, Xiaodan,An, Zhe,Song, Hongyan,Shu, Xin,Xiang, Xu,He, Jing
, p. 9017 - 9027 (2020/12/23)
C-N formation is of great significance to synthetic chemistry, as N-containing products are widely used in chemistry, medicine, and biology. Addition of an amine to an unsaturated carbon-carbon bond is a simple yet effective route to produce new C-N bonds. But how to effectively conduct an anti-Markovnikov addition with high selectivity has been a great challenge. Here, we proposed a strategy for highly regioselective C-N addition via hydroamination by using supported Pt. It has been identified that atomic-scale Pt is the active site for C-N addition with Pt12+ for Markovnikov C-N formation and atomic Pt (Pt1δ+ and Pt10) contributing to anti-Markovnikov C-N formation. A selectivity of up to 92% to the anti-Markovnikov product has been achieved with atomic Pt in the addition of styrene and pyrrolidine. A cooperating catalysis for the anti-Markovnikov C-N formation between Pt1δ+ and Pt10 has been revealed. The reaction mechanism has been studied by EPR spectra and in situ FT-IR spectra of adsorption/desorption of styrene and/or pyrrolidine. It has been demonstrated that Pt10 activates amine to be electrophilic, while Pt1δ+ activates C-C by π-bonding to make β-C nucleophilic. The attack of nucleophilic β-C to electrophilic amine affords the anti-Markovnikov addition. This strategy proves highly effective to a variety of substrates in anti-Markovnikov C-N formation, including aromatic/aliphatic amines reacting with aromatic olefins, aromatic/aliphatic olefins with aromatic amines, and linear aliphatic olefins with secondary aliphatic amines. It is believed that the results provide evidence for the function of varied chemical states in monatomic catalysis.
Transition-Metal-Free Reductive Functionalization of Tertiary Carboxamides and Lactams for α-Branched Amine Synthesis
Chiba, Shunsuke,Dixon, Darren J.,Fan, Dongyang,Ong, Derek Yiren
supporting information, p. 11903 - 11907 (2020/05/22)
A new method for the synthesis of α-branched amines by reductive functionalization of tertiary carboxamides and lactams is described. The process relies on the efficient and controlled reduction of tertiary amides by a sodium hydride/sodium iodide composite, in situ treatment of the resulting anionic hemiaminal with trimethylsilyl chloride and subsequent coupling with nucleophilic reagents including Grignard reagents and tetrabutylammonium cyanide. The new method exhibits broad functional-group compatibility, operates under transition-metal-free reaction conditions, and is suitable for various synthetic applications on both sub-millimole and on multigram scales.
Direct Reductive Amination of Carbonyl Compounds with H2 Using Heterogeneous Catalysts in Continuous Flow as an Alternative to N-Alkylation with Alkyl Halides
Laroche, Benjamin,Ishitani, Haruro,Kobayashi, Shū
supporting information, p. 4699 - 4704 (2018/12/04)
A general continuous-flow procedure for direct reductive amination of secondary and primary amines with aromatic and aliphatic aldehydes as well as ketones is reported. The use of hydrogen gas and commercially available Pt/C as a heterogeneous catalyst is a key. In addition to exhibiting an excellent functional group tolerance, this method allows the fast formation of C?N bonds without production of any hazardous chemical waste. Applications to the synthesis of key intermediates toward active pharmaceutical ingredients (Donepezil and Arformoterol/Tamsulosin) are also described. (Figure presented.).
Expanding the Boundaries of Water-Tolerant Frustrated Lewis Pair Hydrogenation: Enhanced Back Strain in the Lewis Acid Enables the Reductive Amination of Carbonyls
Dorkó, éva,Szabó, Márk,Kótai, Bianka,Pápai, Imre,Domján, Attila,Soós, Tibor
supporting information, p. 9512 - 9516 (2017/08/01)
The development of a boron/nitrogen-centered frustrated Lewis pair (FLP) with remarkably high water tolerance is presented. As systematic steric tuning of the boron-based Lewis acid (LA) component revealed, the enhanced back-strain makes water binding increasingly reversible in the presence of relatively strong base. This advance allows the limits of FLP's hydrogenation to be expanded, as demonstrated by the FLP reductive amination of carbonyls. This metal-free catalytic variant displays a notably broad chemoselectivity and generality.
Efficient and chemoselective reduction of pyridines to tetrahydropyridines and piperidines via rhodium-catalyzed transfer hydrogenation
Wu, Jianjun,Tang, Weijun,Pettman, Alan,Xiao, Jianliang
, p. 35 - 40 (2013/03/13)
Promoted by iodide anion the rhodium complex dimer, [Cp RhCl 2]2, catalyzes efficiently the transfer hydrogenation of various quaternary pyridinium salts under mild conditions, affording not only piperidines but also 1,2,3,6-tetrahydropyridines in a highly chemoselective fashion, depending on the substitution pattern at the pyridinium ring. The reduction is conducted in azeotropic formic acid/triethylamine (HCOOH-Et 3N) mixture at 40 °C, with catalyst loadings as low as 0.005mol% being feasible. Copyright
Highly efficient, base-catalysed, intramolecular hydroamination of non-activated olefins
Quinet, Coralie,Jourdain, Pierre,Hermans, Christophe,Ates, Ali,Lucas, Isabelle,Markó, István E.
, p. 1077 - 1087 (2008/09/17)
The intramolecular hydroamination of a large variety of non-activated alkenes can be efficiently catalysed by small amounts of lithium bases, providing smoothly and in high yields the corresponding five- and six-membered ring heterocycles. Fused and bridged bicyclic amines, of varying ring sizes, can be readily prepared either by a sequential hydroamination process or by a tandem, double addition reaction.
Mild, rhodium-catalyzed intramolecular hydroamination of unactivated terminal and internal alkenes with primary and secondary amines
Liu, Zhijian,Hartwig, John F.
, p. 1570 - 1571 (2008/09/17)
We report a series of mild, rhodium-catalyzed hydroaminations of unactivated olefins with primary and secondary alkylamines to form the corresponding five- and six-membered products in excellent yields. The reactions form exclusively the product from hydroamination without competitive oxidative amination or olefin isomerization with catalysts generated from a biaryl dialkyl phosphine and an analogue of Xantphos. A variety of functional groups were tolerated by the hydroamination process, including hydroxyl, halo, cyano, and carboalkoxyl groups. Copyright
An efficient synthesis of nitrogen heterocycles by Cp*Ir-catalyzed N-cycloalkylation of primary amines with diols
Fujita, Ken-ichi,Fujii, Takeshi,Komatsubara, Atsuo,Enoki, Youichiro,Yamaguchi, Ryohei
, p. 673 - 682 (2008/09/18)
A new efficient method for the N-cycloalkylation of primary amines with diols catalyzed by a Cp*Ir complex have been developed. A variety of five-, six-, and seven-membered cyclic amines are synthesized in good to excellent yields in environmentally benign and atom economical manner with the formation of only water as a coproduct. A large scale synthesis of N-benzylpiperidine and a two-step asymmetric synthesis of (S)-2-phenylpiperidine using (R)-1-phenylethylamine as a starting primary amine have been also achieved.
Cp*Ir complex-catalyzed N-heterocyclization of primary amines with diols: A new catalytic system for environmentally benign synthesis of cyclic amines
Fujita, Ken-Ichi,Fujii, Takeshi,Yamaguchi, Ryohei
, p. 3525 - 3528 (2007/10/03)
(Chemical Equation Presented) A new efficient method for the N-heterocyclization of primary amines with diols catalyzed by a Cp*Ir complex was developed. A variety of five-, six-, and seven-membered cyclic amines were synthesized in good to excellent yields with the formation of only water as a byproduct. A two-step asymmetric synthesis of (S)-2-phenylpiperidine was also achieved using (R)-1-phenylethylamine as a starting primary amine.
