scholarly journals Ni-catalyzed regio- and stereo-defined intermolecular cross-electrophile dialkylation of alkynes without directing group

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi-Zhou Zhan ◽  
Nan Xiao ◽  
Wei Shu
Keyword(s):  
Room Temperature ◽  
Single Electron ◽  
Efficient Synthesis ◽  
Organometallic Reagents ◽  
Mild Conditions ◽  
Synthetic Utility ◽  
Directing Group ◽  
Hydride Elimination

AbstractThe development of straightforward synthesis of regio- and stereodefined alkenes with multiple aliphatic substituents under mild conditions is an unmet challenge owing to competitive β-hydride elimination and selectivity issues. Herein, we report the nickel-catalyzed intermolecular cross-dialkylation of alkynes devoid of directing or activating groups to afford multiple aliphatic substituted alkenes in a syn-selective fashion at room temperature. The combination of two-electron oxidative cyclometallation and single-electron cross-electrophile coupling of nickel enables the syn-cross-dialkylation of alkynes at room temperature. This reductive protocol enables the sequential installation of two different alkyl substituents onto alkynes in a regio- and stereo-selective manner, circumventing the tedious preformation of sensitive organometallic reagents. The synthetic utility of this protocol is demonstrated by efficient synthesis of multi-substituted unfunctionalized alkenes and diverse transformations of the product.

Rh(iii)-Catalyzedortho-C–H alkynylation ofN-phenoxyacetamides with hypervalent iodine-alkyne reagents at room temperature

2018 ◽  
Vol 16 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Sisheng Hu ◽  
Liang Lu ◽  
Tongyang Zhu ◽  
Qian Wu ◽  
Ying Chen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hypervalent Iodine ◽  
Mild Conditions ◽  
Directing Group

Directing group ONHR preservedortho-alkynylation under mild conditions catalyzed by rhodium is reported.

Access to Highly Substituted Pyrimidine N-Oxides and 4-Acetoxymethyl-Substituted Pyrimidines via the LANCA Three-Component Reaction–Cyclocondensation Sequence

Synthesis ◽  
2021 ◽  
Author(s):  
Reinhold Zimmer ◽  
Hans-Ulrich Reissig ◽  
Luise Schefzig ◽  
Timon Kurzawa ◽  
Giaime Rancan ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Room Temperature ◽  
Hydroxylamine Hydrochloride ◽  
Trifluoroacetic Anhydride ◽  
Pyrimidine Derivatives ◽  
Mild Conditions ◽  
Structural Variety ◽  
Three Component Reaction ◽  
Sterically Demanding ◽  
Synthetic Utility

AbstractThe LANCA three-component reaction of lithiated alkoxy­allenes (LA), nitriles (N), and carboxylic acids (CA) smoothly provides β-alkoxy-β-ketoenamides in broad structural variety. The subsequent cyclocondensation of these compounds with hydroxylamine hydrochloride afforded a large library of pyrimidine N-oxides under mild conditions and in good yields. Their synthetic utility was further increased by the Boekelheide rearrangement leading to 4-acetoxymethyl-substituted pyrimidines. With trifluoroacetic anhydride the rearrangement proceeds even at room temperature and directly furnishes 4-hydroxymethyl-substituted pyrimidine derivatives. The key reactions are very robust and work well even in the presence of sterically demanding substituents.

Silver-Catalyzed para-Selective C–H Amination of 1-Naphthyl­amides with Azodicarboxylates at Room Temperature

Synthesis ◽  
2019 ◽  
Vol 51 (13) ◽  
pp. 2697-2704 ◽  
Author(s):  
Quan-Zhe Li ◽  
Xun-Hui Wang ◽  
Si-Hua Hou ◽  
Yan-Yan Ma ◽  
Deng-Gao Zhao ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Transfer Process ◽  
Room Temperature ◽  
Reaction System ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Electron Transfer Process ◽  
Silver Catalysis ◽  
Directing Group

A simple and efficient protocol for para-selective C–H amination of 1-naphthylamide derivatives under silver catalysis is described. This reaction system could proceed without the help of directing group and a broad range of substrates were proved to be well tolerated. In addition, control experiments suggested that this reaction might not proceed via a single-electron-transfer process.

A Green Approach to the Synthesis of Novel Indole Substituted 2-Amino- 4,5-dihydro-3-furancarbonitriles in Water

2019 ◽  
Vol 16 (3) ◽  
pp. 209-214
Author(s):  
Pannala Padmaja ◽  
Pedavenkatagari Narayana Reddy ◽  
Bijaya Ketan Sahoo
Keyword(s):  
Sodium Borohydride ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
One Pot ◽  
Catalyst Free ◽  
Green Approach ◽  
Three Component Reaction ◽  
Wide Range ◽  
Synthetic Utility ◽  
Synthetic Intermediates

2-Amino-4,5-dihydro-3-furancarbonitriles (ADFCs) have attracted much attention due to their utility as valuable synthetic intermediates for the preparation of a series of acyclic and cyclic organic compounds. On the other hand, indoles substituted with furans are highly interesting compounds displaying a wide range of biological and pharmaceutical activities. However, to the best of our knowledge, indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles have not been previously reported. A new and efficient synthesis of indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles has been developed in two steps using water as a solvent. The first step of the sequence involves threecomponent reaction of phenylglyoxals, indoles and malononitrile under aqueous and catalyst-free conditions for the synthesis of indole substituted β,β-dicyanoketones. Reduction of the obtained β,β- dicyanoketones with sodium borohydride in water at room temperature afforded the indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles in good yields. Several substituted phenylglyooxals were reacted smoothly with indole or 2-methylindole and malononitrile to give the corresponding indole substituted β,β-dicyanoketones in good yields. Treatment of the obtained β,β-dicyanoketones with sodium borohydride in water furnished exclusively the indole substituted 2-amino-4,5-dihydro-3- furancarbonitriles in good yields. We have developed an efficient straightforward access to indole substituted β,β-dicyanoketones by one-pot three-component reaction of phenylglyoxals, indoles and malononitrile. The synthetic utility of obtained indole substituted β,β-dicyanoketones has been outlined by the preparation of indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles. The advantage of catalyst-free, atom-economical and environmental benignity render it promising methods for preparation of indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles.

scholarly journals An Efficient Greener Approach for N-acylation of Amines in Water Using Benzotriazole Chemistry

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2501 ◽  
Author(s):  
Tarek S. Ibrahim ◽  
Israa A. Seliem ◽  
Siva S. Panda ◽  
Amany M. M. Al-Mahmoudy ◽  
Zakaria K. M. Abdel-Samii ◽  
...  
Keyword(s):  
Amino Acid ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
Short Reaction Time ◽  
Mild Conditions ◽  
Drug Conjugates ◽  
Cost Efficient ◽  
High Yields

A straightforward, mild and cost-efficient synthesis of various arylamides in water was accomplished using versatile benzotriazole chemistry. Acylation of various amines was achieved in water at room temperature as well as under microwave irradiation. The developed protocol unfolds the synthesis of amino acid aryl amides, drug conjugates and benzimidazoles. The environmentally friendly synthesis, short reaction time, simple workup, high yields, mild conditions and free of racemization are the key advantages of this protocol.

Cobalt(III)-catalyzed redox-neutral [4+2]-annulation of N-chlorobenzamides/acrylamides with alkylidenecyclopropanes at room temperature

2021 ◽  
Author(s):  
Masilamani Jeganmohan ◽  
Balu Ramesh
Keyword(s):  
Room Temperature ◽  
Efficient Synthesis ◽  
Directing Group

An efficient synthesis of substituted 3,4-dihydroisoquinolinones through [4+2]-annulation of N-chlorobenzamides/acrylamides having a monodentate directing group with alkylidenecyclopropanes in the presence of a less expensive, highly abundant and air stable Co(III)...

Facile and efficient synthesis of 1-haloalkynes via DBU-mediated reaction of terminal alkynes and N-haloimides under mild conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (57) ◽  
pp. 30046-30049 ◽  
Author(s):  
Mengru Li ◽  
Yueju Li ◽  
Baozhong Zhao ◽  
Fushun Liang ◽  
Long-Yi Jin
Keyword(s):  
Room Temperature ◽  
Terminal Alkynes ◽  
Efficient Synthesis ◽  
Mild Conditions

Directly from terminal alkynes and with N-halosuccinimides (halo = Br and I) or N-cholorophthalimide as the halogen sources, DBU as the activator, 1-haloalkynes were prepared in good to excellent yields at room temperature.

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis

2019 ◽  
Author(s):  
Andrew Romine ◽  
Kin Yang ◽  
Malkanthi Karunananda ◽  
Jason Chen ◽  
Keary Engle
Keyword(s):  
Mechanistic Studies ◽  
Salvianolic Acid ◽  
Wide Range ◽  
Computational Data ◽  
Synthetic Utility ◽  
Directing Group ◽  
High Yields ◽  
Julia Olefination ◽  
Reaction Progress Kinetic Analysis

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.

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