Selective Synthesis of Imines and Secondary Amines by Homocoupling of Primary Amines

Synfacts ◽  
2021 ◽  
Vol 17 (10) ◽  
pp. 1127
2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>


1985 ◽  
Vol 50 (8) ◽  
pp. 1888-1898 ◽  
Author(s):  
Miroslav Protiva ◽  
Zdeněk Šedivý ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Jiří Němec

Reactions of naphthostyril (I) with primary and secondary amines and titanium tetrachloride afforded cyclic amidines III-IX. Hydrogenation of I on Pd-C resulted in the 6,7,8,8a-tetrahydro derivative X which gave by treatment with sodium amide and 3-dimethylaminopropyl chloride the N-(aminoalkyl) compound XI. Reduction of I and its N-methyl derivative II with sodium amalgam in aqueous sodium hydroxide gave the 2a,3,4,5-tetrahydro derivatives XII and XIII. Reaction of XIII with sodium amide and 3-dimethylaminopropyl chloride afforded the 2a-(aminoalkyl) compound XIV. 1,3,4,5-Tetrahydro-1-benzazepin-2-one (XV) treated with primary amines and titanium tetrachloride gave the amidines XVI-XVIII. 3-Methyl-7,8,9,9a-tetrahydro-1H-benz[d,e]isoquinoline (XIX) was reduced with sodium borohydride to compound XX which was alkylated with propargyl bromide to 1-methyl-2-propargyl-2,3,3a,4,5,6-hexahydro-1H-benz[d,e]isoquinoline (XXI). An attempt to prepare the 2-(2-phenylethyl) analogue by treatment of compound XX with phenylacetyl chloride and by the following reduction with lithium aluminium hydride resulted in the open-chain amine XXII. The lactams I, II, X, and XIII showed some discoordinating, hypothermic, peripheral vasodilating, hyperglycaemic, diuretic and antiinflammatory effects. The amidines III-IX and XVI-XVIII had local anaesthetic, slight hypotensive, antiarrhythmic, peripheral myorelaxant, papaverine-like spasmolytic and thiopental potentiating effects.


2007 ◽  
Vol 11 (07) ◽  
pp. 537-546 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Annette Hiebert ◽  
Sibel Ok

Primary amines, secondary amines and tertiary butyl esters of amino acids are used as nucleophiles with zinc(II) hexadecafluorophthalocyanine to provide mixtures of mono and disubstituted fluorinated phthalocyanines under mild conditions, or polyaminosubstituted phthalocyanines when using the amines as solvents. Diamines give cyclic substituted phthalocyanines, binuclear or trinuclear phthalocyanines or mixtures of both types, depending on the chain length or structure of the diamine.


2020 ◽  
Author(s):  
Brian J Wang ◽  
Matthew Duncton

<div> <p>The azetidine group is frequently encountered within contemporary medicinal chemistry where it is viewed as a privileged structure. However, the introduction of an azetidine can be synthetically challenging. Herein, a straight-forward one step synthesis of azetidine-3-amines, starting from a bench stable, commercial material is presented. The reaction tolerates functional groups commonly encountered in biological-, medicinal- and agro-chemistry, and proceeds in moderate-to-high yield with secondary amines, and moderate-to-low yield with primary amines. The methodology compares favorably to recent alternative procedures and can be utilized in “any-stage” functionalization, including late-stage azetidinylation of approved drugs and other compounds with pharmacological activity.</p> </div>


ChemCatChem ◽  
2015 ◽  
Vol 7 (6) ◽  
pp. 921-924 ◽  
Author(s):  
Yoichi Nakamura ◽  
Kenichi Kon ◽  
Abeda Sultana Touchy ◽  
Ken-ichi Shimizu ◽  
Wataru Ueda

2018 ◽  
Vol 73 (1) ◽  
pp. 43-74 ◽  
Author(s):  
Cindy Döring ◽  
Peter G. Jones

AbstractThe reaction of (tht)AuX (X=Cl or Br; tht=tetrahydrothiophene) with various primary amines L leads to products of the form [L2Au]+X−. Packing diagrams of the corresponding structures are dominated by N–H···X hydrogen bonds and (in some cases) aurophilic contacts. The cyclohexylamine derivative was already known as its dichloromethane ⅔-solvate; we have isolated the solvent-free compound and its pentane ¼-solvate, which all show different packing patterns. With acyclic secondary amines, the products are more varied; LAuX and [L2Au]+[AuX2]− were also found. These gold(I) products were generally formed in satisfactory quantities. The attempted oxidation to Au(III) derivatives with PhICl2 or Br2 proved impossible for the primary amine derivatives [although isopropylamine-trichloridogold(III) was obtained unexpectedly from the corresponding cyanide] and unsatisfactory for the secondary amine derivatives. Products LAuX3 and [L2AuX2]+[AuX4]− were identified but were formed in disappointing yields. In isolated cases protonated products (LH)+[AuCl4]−, (LH+)3[AuCl4]−(Cl−)2 or [(Et2N)2CH]+[AuBr4]− were formed, presumably by involvement of the dichloromethane solvent and/or adventitious water. Here also the yields were poor, and some products arose as mixtures. Direct reaction of amines with AuCl3 or (tht)AuX3 was also unsuccessful. All products were characterized by X-ray structure analysis.


Author(s):  
Douglass F. Taber

Bekington Myrboh of North-Eastern Hill University reported (Tetrahedron Lett. 2010, 51, 2862) a convenient procedure for the oxidative removal of a 1,3-oxathiolane 1 or a 1,3-dithiolane. Sang-Gyeong Lee and Yong-Jin Yoon of Gyeongsang National University developed (J. Org. Chem. 2010, 75, 484) the pyridazin-3(2H )-one 4 for the microwave-mediated deprotection of an oxime 3. Dario M. Bassani of Université Bordeaux 1 and John S. Snaith of the University of Birmingham devised (J. Org. Chem. 2010, 75, 4648) a procedure for the facile preparation of esters such as 6. Brief photolysis (350 nm) returned the parent carboxylic acid 7. Craig M. Williams of the University of Queensland prepared (Tetrahedron Lett. 2010, 51, 1158) the trithioorthoester 8 by iterative opening of epichlorohydrin. He found that the keto ester 9 could be efficiently released by Hg-mediated hydrolysis. Masatoshi Mihara of the Osaka Municipal Technical Research Institute established (Synlett 2010, 253) that even very congested alcohols such as 10 could be acetylated by acetic anhydride containing a trace of FeCl3. Colleen N. Scott, now at Southern Illinois University, developed (J. Org. Chem. 2010, 75, 253) a convenient procedure for the preparation of the hydridosilane 13, which on Mn catalysis added the alcohol 12 to make the unsymmetrical bisalkoxysilane 14. Sabine Berteina-Raboin of the Université d’Orléans found (Tetrahedron Lett. 2010, 51, 2115) that NaBH4 in EtOH cleanly removed the chloroacetates from 15. Both other esters and silyl ethers were stable under these conditions. Ram S. Mohan of Illinois Wesleyan University established (Tetrahedron Lett. 2010, 51, 1056) that Fe(III) tosylate in methanol selectively removed the alkyl silyl ether from 17 without affecting the aryl silyl ether. Alakananda Hajra and Adinath Majee of Visva-Bharati University effected (Tetrahedron Lett. 2010, 51, 2896) formylation of an amine 19 by heating with commercial 85% formic acid as the solvent in a sealed tube at 80°C. Although both primary and secondary amines could be effi ciently formylated, the primary amines were much more reactive. Doo Ok Jang of Yonsei University found (Tetrahedron Lett. 2010, 51, 683) that the conveniently handled CF3CCO2H (the acid chloride is a gas) could be activated in situ to selectively convert 22 into 24.


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