17027-51-9Relevant academic research and scientific papers
Direct Access to Primary Amines from Alkenes by Selective Metal-Free Hydroamination
Du, Yi-Dan,Chen, Bi-Hong,Shu, Wei
supporting information, p. 9875 - 9880 (2021/03/29)
Direct and selective synthesis of primary amines from easily available precursors is attractive yet challenging. Herein, we report the rapid synthesis of primary amines from alkenes via metal-free regioselective hydroamination at room temperature. Ammonium carbonate was used as ammonia surrogate for the first time, allowing for efficient conversion of terminal and internal alkenes into linear, α-branched, and α-tertiary primary amines under mild conditions. This method provides a straightforward and powerful approach to a wide spectrum of advanced, highly functionalized primary amines which are of particular interest in pharmaceutical chemistry and other areas.
Pd-Catalyzed Suzuki coupling reactions of aryl halides containing basic nitrogen centers with arylboronic acids in water in the absence of added base
Li, Zhao,Gelbaum, Carol,Campbell, Zachary S.,Gould, Paul C.,Fisk, Jason S.,Holden, Bruce,Jaganathan, Arvind,Whiteker, Gregory T.,Pollet, Pamela,Liotta, Charles L.
supporting information, p. 15420 - 15432 (2017/12/15)
The Pd-catalyzed Suzuki coupling reactions of a series of aryl chlorides and aryl bromides containing basic nitrogen centers with arylboronic acids in water in the absence of added base are reported. The reactions proceed either partially or entirely under acidic conditions. After surveying twenty-two phosphorus ligands, high yields of products were obtained with aryl chlorides only when a bulky ligand, 2-(di-tert-butyl-phosphino)-1-phenyl-1H-pyrrole (cataCXiumPtB) was used. In contrast, aryl bromides produced high yields of products in the absence of both added base and added ligand. In order to explore the Suzuki coupling process entirely under acidic conditions, a series of reactions were conducted in buffered acidic media using several model substrates. 4-Chlorobenzylamine, in the presence of cataCXiumPtB, produced high yields of product at buffered pH 6.0; the yields dropped off precipitously at buffered pH 5.0 and lower. The fall-off in yield was attributed to the decomposition of the Pd-ligand complex due to the protonation of the ligand in the more acidic aqueous media. In contrast, in the absence of an added ligand, 4-amino-2-chloropyridine produced quantitative yields at buffered pH 3.5 and 4.5 while 4-amino-2-bromopyridine produced quantitative yields in a series of buffered media ranging from pH 4.5 to 1.5. These substrates are only partially protonated in acidic media and can behave as active Pd ligands in the Suzuki catalytic cycle.
METHODS FOR EXTERNAL BASE-FREE SUZUKI COUPLINGS
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Paragraph 0040-0041, (2017/07/14)
The present disclosure describes a method of coupling a first aromatic compound to a second aromatic compound, the method comprising: (a) preparing a reaction mixture comprising the first aromatic compound, the second aromatic compound, a catalyst and water; the reaction mixture does not contain an external base, the reaction mixture having an initial pH of from 11 to 1; the catalyst having at least one group 10 atom; the first aromatic compound having a halogen, triflate or sulfonate substituent; the second aromatic compound having a boron-containing substituent; wherein, at least one of the first aromatic compound or the second aromatic compound includes one or more heteroatom; and (b) reacting the first aromatic compound and the second aromatic compound in the reaction mixture, the reaction mixture having a final pH following reaction of the first aromatic compound and the second aromatic compound.
Aqueous Suzuki Coupling Reactions of Basic Nitrogen-Containing Substrates in the Absence of Added Base and Ligand: Observation of High Yields under Acidic Conditions
Li, Zhao,Gelbaum, Carol,Fisk, Jason S.,Holden, Bruce,Jaganathan, Arvind,Whiteker, Gregory T.,Pollet, Pamela,Liotta, Charles L.
, p. 8520 - 8529 (2016/09/28)
A series of aqueous heterogeneous Suzuki coupling reactions of substrates containing basic nitrogen centers with phenylboronic acid in the absence of added base and ligand is presented. High yields of products were obtained by employing aryl bromides containing aliphatic 1°, 2°, and 3° amine substituents, and good to high yields were obtained by employing a variety of substituted bromopyridines. In the former series, the pH of the aqueous phase changed from basic to acidic during the course of the reaction, while in the latter series the aqueous phase was on the acidic side of the pH scale throughout the entire course of reaction. A mechanistic interpretation for these observations, which generally preserves the oxo palladium catalytic cycle widely accepted in the literature, is presented.
Nickel-catalyzed cross-coupling of aryl grignard reagents with aromatic alkyl ethers: An efficient synthesis of unsymmetrical biaryls
Dankwardt, John W.
, p. 2428 - 2432 (2007/10/03)
New substrates for biaryl synthesis: aromatic ethers undergo nickel-catalyzed cross-coupling with aryl Grignard reagents to give unsymmetrical biaryls in excellent yields (see scheme). Both the nature of the nickel catalyst and the choice of solvent are crucial for reaching high levels of conversion.
