scholarly journals Catalytic C(sp3)−H Arylation of Free Primary Amines with anexoDirecting Group Generated In Situ

2016 ◽  
Vol 128 (31) ◽  
pp. 9230-9233 ◽  
Author(s):  
Yan Xu ◽  
Michael C. Young ◽  
Chengpeng Wang ◽  
David M. Magness ◽  
Guangbin Dong
Keyword(s):  
Primary Amines

scholarly journals Metal-Free Air Oxidation in a Convenient Cascade Approach for the Access to Isoquinoline-1,3,4(2H)-triones

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2177
Author(s):  
Antonia Di Mola ◽  
Consiglia Tedesco ◽  
Antonio Massa
Keyword(s):  
Heterocyclic Compounds ◽  
Aromatic Ketone ◽  
Primary Amines ◽  
Cascade Process ◽  
Staudinger Reaction ◽  
Caspase Inhibitor ◽  
Air Oxidation ◽  
Metal Free ◽  
Free Air

Herein we describe a very useful application of the readily available trifunctional aromatic ketone methyl-2-(2-bromoacetyl)benzoate in reactions with primary amines. An unexpected in situ air oxidation that follows a cascade process allowed the access to a series of isoquinoline-1,3,4(2H)-triones, a class of heterocyclic compounds of great interest containing an oxygen-rich heterocyclic scaffold. A modification of the original protocol, utilizing a Staudinger reaction in the presence of trimethylphosphine, was necessary for the synthesis of Caspase inhibitor trione with free NH group.

Functional Group Protection

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Secondary Amines ◽  
Primary Amines ◽  
Silyl Ether ◽  
Southern Illinois ◽  
Convenient Procedure ◽  
North Eastern ◽  
National University ◽  
Facile Preparation ◽  
The University

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.

scholarly journals A dual biomimetic process for the selective aerobic oxidative coupling of primary amines using pyrogallol as a precatalyst. Isolation of the [5 + 2] cycloaddition redox intermediates

2020 ◽  
Vol 22 (6) ◽  
pp. 1894-1905 ◽  
Author(s):  
Martine Largeron ◽  
Patrick Deschamps ◽  
Karim Hammad ◽  
Maurice-Bernard Fleury
Keyword(s):  
Oxidative Coupling ◽  
Low Cost ◽  
Primary Amines ◽  
Processing Step

Low-cost pyrogallol precatalyst undergoes an oxidative self-processing step for delivering the active organocatalyst in situ through a dual biomimetic process.

Metal-Free Oxidative C(sp3)–N Coupling by HBr and DMSO: A Novel Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 912-917 ◽  
Author(s):  
Parviz Ranjbar ◽  
Narjes Rezaei ◽  
Ehsan Sheikhi
Keyword(s):  
Oxidative Cyclization ◽  
Cyclization Reaction ◽  
Primary Amines ◽  
Isatoic Anhydride ◽  
Reaction Conditions ◽  
Coupling Process ◽  
Benzylic Alcohols ◽  
Metal Free ◽  
Novel Synthesis

A metal-free oxidative C(sp3)–N coupling process has been developed for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones. The reaction between primary amines, isatoic anhydride, and benzylic alcohols in the presence of HBr in DMSO at 80 °C affords 2,3-dihydroquinazolin-4(1H)-ones in excellent yields. Under these reaction conditions, benzylic alcohols react with in situ generated bromodimethylsulfonium bromide to form alkoxysulfonium intermediates. These intermediates undergo an oxidative cyclization reaction with primary amines and isatoic anhydride to produce the title products.

scholarly journals Catalytic C(sp3 )−H Arylation of Free Primary Amines with an exo Directing Group Generated In Situ

2016 ◽  
Vol 55 (31) ◽  
pp. 9084-9087 ◽  
Author(s):  
Yan Xu ◽  
Michael C. Young ◽  
Chengpeng Wang ◽  
David M. Magness ◽  
Guangbin Dong
Keyword(s):  
Primary Amines ◽  
Directing Group

scholarly journals Bio-Inspired Primary Amine α-C–H Functionalization

2018 ◽  
Author(s):  
Dhananjayan Vasu ◽  
Ángel L. Fuentes de Arriba ◽  
Jamie A. Leitch ◽  
Antoine de Gombert ◽  
Darren J. Dixon
Keyword(s):  
Drug Discovery ◽  
Late Stage ◽  
Primary Amine ◽  
Amine Oxidase ◽  
Primary Amines ◽  
Reverse Polarity ◽  
Copper Amine Oxidase ◽  
Drug Molecules ◽  
Organolithium Reagents

<div>The selective manipulation of complex amine architectures has received great attention in recent years with widespread applications including inter alia drug discovery. Inspired by an enzymatic copper amine oxidase process, a synthetic quinone co-factor mediated general platform for the construction of α-fully substituted primary amines from abundant α-branched primary amine starting materials is described. This procedure pivots on the efficient generation of reactive ketimine intermediates in situ which are primed to react with carbon-centered nucleophiles such as organomagnesium and organolithium reagents, and TMSCN. Extension to reverse polarity photoredox catalysis enables reactivity with electrophiles. Subsequent oxidative hydrolysis releases the unprotected α-fully substituted primary amine product. This efficient, broadly applicable and scaleable amine-to-amine synthetic platform was successfully applied to library and API synthesis and in the late stage functionalization of drug molecules.</div>

scholarly journals Recent Advances in the Synthesis of Isothiocyanates Using Elemental Sulfur

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1081
Author(s):  
András Gy. Németh ◽  
Péter Ábrányi-Balogh
Keyword(s):  
Natural Products ◽  
Best Practices ◽  
Organic Synthesis ◽  
Elemental Sulfur ◽  
Biologically Active ◽  
Primary Amines ◽  
Pharmaceutical Ingredients ◽  
Recent Developments ◽  
In Situ Generation

Isothiocyanates (ITCs) are biologically active molecules found in several natural products and pharmaceutical ingredients. Moreover, due to their high and versatile reactivity, they are widely used as intermediates in organic synthesis. This review considers the best practices for the synthesis of ITCs using elemental sulfur, highlighting recent developments. First, we summarize the in situ generation of thiocarbonyl surrogates followed by their transformation in the presence of primary amines leading to ITCs. Second, carbenes and amines afford isocyanides, and the further reaction of this species with sulfur readily generates ITCs under thermal, catalytic or basic conditions. Additionally, we also reveal that in the catalyst-free reaction of isocyanides and sulfur, two—until this time overlooked and not investigated—different mechanistic pathways exist.

Direct Asymmetric Mannich Reaction Catalyzed by a d-Glucosamine-Derived Organocatalyst

Synlett ◽  
2018 ◽  
Vol 29 (05) ◽  
pp. 630-634 ◽  
Author(s):  
Rama Peddinti ◽  
Arun Sharma
Keyword(s):  
Hydrogen Bonding ◽  
Mannich Reaction ◽  
Carbonyl Compounds ◽  
Enantiomeric Excess ◽  
Primary Amines ◽  
Screening Experiments ◽  
Catalyst Screening

Sugar-based primary amines have been employed as organocatalysts for the direct asymmetric Mannich reaction. By catalyst-screening experiments, we observed that catalysts bearing a hydroxy function at C-3 actively participated in the reaction, possibly through hydrogen bonding with the imine generated in situ, to provide β-amino carbonyl compounds with better diastereoselectivity and enantioselectivity. All the products were obtained in good to excellent enantiomeric excess.

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