scholarly journals Collective synthesis of acetylenic pharmaceuticals via enantioselective Nickel/Lewis acid-catalyzed propargylic alkylation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xihao Chang ◽  
Jiayin Zhang ◽  
Lingzi Peng ◽  
Chang Guo
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Groups ◽  
Bioactive Compounds ◽  
Lewis Acid ◽  
Mild Condition ◽  
Substitution Reaction ◽  
Biologically Active ◽  
Acid Catalyzed ◽  
Propargylic Substitution

AbstractChiral acetylenic derivatives are found in many bioactive compounds and are versatile functional groups in organic chemistry. Here, we describe an enantioselective nickel/Lewis acid-catalyzed asymmetric propargylic substitution reaction from simple achiral materials under mild condition. The introduction of a Lewis acid cocatalyst is crucial to the efficiency of the transformation. Notably, we investigate this asymmetric propargylic substitution reaction for the development of a range of structurally diverse natural products. The power of this strategy is highlighted by the collective synthesis of seven biologically active compounds: (−)-Thiohexital, (+)-Thiopental, (+)-Pentobarbital, (−)-AMG 837, (+)-Phenoxanol, (+)-Citralis, and (−)-Citralis Nitrile.

Accessing Polycyclic Terpenoids from Zerumbone via Lewis Acid Catalyzed Synthetic Strategies

Synthesis ◽  
2020 ◽  
Vol 52 (14) ◽  
pp. 2045-2064 ◽  
Author(s):  
Puthiyaparambath Sharathna ◽  
Murugan Thulasi Meenu ◽  
Kokkuvayil Vasu Radhakrishnan ◽  
Bhandara Purayil Dhanya ◽  
Greeshma Gopalan ◽  
...  
Keyword(s):  
Natural Products ◽  
Lewis Acid ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Effective Strategy ◽  
Structural Elements ◽  
Nazarov Cyclization ◽  
Active Compounds ◽  
Acid Catalyzed

We herein disclose an effective strategy for the synthesis of [5.3.0] and [6.3.0] fused polycyclic terpenoids, which are important structural elements of natural products and biologically active compounds. The method comprises of Lewis acid catalyzed interrupted Nazarov cyclization of zerumbone derivatives such as zerumbone epoxide, triazole-appended zerumbone, zerumbal, and zerumbenone with a wide substrate scope with different indoles. Zerumbone epoxide furnished [5.3.0] and [6.3.0] fused structurally diverse sesquiterpenoids and all other zerumbone derivatives furnished the [6.3.0] fused motifs.

Lewis-Acid-Catalyzed Direct Nucleophilic Substitution Reaction of Alcohols for the Functionalization of Aromatic Amines

2019 ◽  
Vol 4 (4) ◽  
pp. 1371-1374 ◽  
Author(s):  
Onkar S. Nayal ◽  
Maheshwar S. Thakur ◽  
Rohit Rana ◽  
Rahul Upadhyay ◽  
Sushil K. Maurya
Keyword(s):  
Nucleophilic Substitution ◽  
Lewis Acid ◽  
Aromatic Amines ◽  
Substitution Reaction ◽  
Nucleophilic Substitution Reaction ◽  
Acid Catalyzed

Oxidative cyclization for the synthesis of complex tetrahydrofuran-containing natural products

2013 ◽  
Vol 85 (6) ◽  
pp. 1175-1184 ◽  
Author(s):  
Robert D. C. Pullin ◽  
Radosław M. Lipiński ◽  
Timothy J. Donohoe
Keyword(s):  
Natural Products ◽  
Amino Acid ◽  
Functional Groups ◽  
Lewis Acid ◽  
Excitatory Amino Acid ◽  
Oxidative Cyclization ◽  
Annonaceous Acetogenins ◽  
Hydride Shift ◽  
Vicinal Diols ◽  
Shift Sequence

The osmium-catalyzed oxidative cyclization of vicinal diols onto proximal olefins to generate 2,5-cis-substituted tetrahydrofurans (THFs) has been exploited as the key step for the construction of several complex THF-containing natural products, namely, the annonaceous acetogenins cis-sylvaticin, sylvaticin, and the excitatory amino acid neo-dysiherbaine A. Recently modified conditions that employ a Lewis acid enable the cyclization to proceed under milder conditions, providing greater tolerance to acid-sensitive functional groups, as demonstrated in two of the syntheses. Flexibility for the construction of 2,5-trans-THFs was demonstrated in the synthesis of sylvaticin by utilization of an intramolecular hydride-shift sequence.

scholarly journals Recent applications of imines as key intermediates in the synthesis of alkaloids and novel nitrogen heterocycles

2009 ◽  
Vol 81 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Stephen F. Martin
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Multicomponent Reactions ◽  
Nitrogen Heterocycles ◽  
Biologically Active ◽  
Total Syntheses ◽  
Biological Interest ◽  
Cascade Processes ◽  
Novel Applications ◽  
Active Natural

One of the major challenges in contemporary synthetic organic chemistry is the design and development of new tactics and strategies and their application to concise and efficient syntheses of biologically active natural products. Strategies that utilize reactions that enable the rapid assembly of the skeletal framework of such targets are thus especially attractive. In this context, we have developed novel applications of imine chemistry in Mannich and related reactions, cascade processes, and multicomponent reactions (MCRs) to rapidly assemble structural subunits common to diverse families of alkaloids. The practical utility of these chemistries is evidenced by their use in the execution of facile total syntheses of (±)-epilupinine (1), (±)-tashiromine (2), (-)-epimyrtine (3), and (±)-roelactamine (4) as well as other nitrogen heterocycles of potential biological interest.

Nucleophilic Cyclization/Electrophilic Substitution of (2,2-Dialkoxyethyl)ureas: Highly Regioselective Access to Novel 4-(Het)arylimidazolidinones and Benzo[d][1,3]diazepinones

Synthesis ◽  
2020 ◽  
Vol 52 (21) ◽  
pp. 3263-3271
Author(s):  
Andrey V. Smolobochkin ◽  
Almir S. Gazizov ◽  
Nazerke K. Otegen ◽  
Julia K. Voronina ◽  
Anna G. Strelnik ◽  
...  
Keyword(s):  
Substitution Reaction ◽  
Electrophilic Substitution ◽  
Biologically Active ◽  
Electrophilic Substitution Reaction ◽  
Reaction Sequence ◽  
Active Compounds ◽  
Acid Catalyzed ◽  
High Yields ◽  
Nucleophilic Cyclization ◽  
Mechanism Of The Reaction

Imidazolidin-2-one and 1,3-benzodiazepin-2-one scaffolds are structural motifs of many biologically active compounds. Herein, we report a highly regioselective acid-catalyzed intramolecular nucleophilic cyclization/intermolecular electrophilic substitution reaction sequence of (2,2-dialkoxyethyl)ureas. The reaction benefits from readily available starting materials, a simple workup procedure, moderate to high yields of target compounds, and provides a convenient entry to previously unknown 4-(het)arylimidazolidinones and 5-(het)arylbenzodiazepinones. The proposed mechanism of the reaction is also discussed.

Tandem allylboration-ring-closing metathesis reactions for the preparation of biologically active molecules

2003 ◽  
Vol 75 (9) ◽  
pp. 1263-1275 ◽  
Author(s):  
P. Veeraraghavan Ramachandran ◽  
M. Venkat Ram Reddy ◽  
Herbert C. Brown
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Asymmetric Synthesis ◽  
Biologically Active ◽  
Cyclic Ethers ◽  
Ring Closing Metathesis ◽  
The Past ◽  
Metathesis Reactions

The development of asymmetric synthesis during the past two decades aided organic chemists considerably in the synthesis of complex natural products. Organoborane chemistry continues to play an important role in asymmetric synthesis. One of the important reactions that has become very common in the arsenal of synthetic chemists is allylboration and related reactions. Another important reaction that has recently attained enormous importance in organic chemistry is the ring-closing metathesis (RCM) reaction. Indeed, a combination of allylboration and RCM reactions provides an excellent route to cyclic ethers, lactones, lactams, etc. Herein, we describe a sequential asymmetric allylboration and RCM reaction protocol that has been utilized for the synthesis of several alpha-pyrone-containing natural products,particularly biologically active molecules.

scholarly journals Protecting group free enantiospecific total syntheses of structurally diverse natural products of the tetrahydrocannabinoid family

2015 ◽  
Vol 51 (14) ◽  
pp. 2871-2873 ◽  
Author(s):  
Dattatraya H. Dethe ◽  
Rohan D. Erande ◽  
Samarpita Mahapatra ◽  
Saikat Das ◽  
Vijay Kumar B.
Keyword(s):  
Natural Products ◽  
Lewis Acid ◽  
Allylic Alcohol ◽  
Protecting Group ◽  
Total Syntheses ◽  
Acid Catalyzed

A simple, highly diastereoselective, Lewis acid catalyzed Friedel–Crafts coupling of a cyclic allylic alcohol with resorcinol derivatives has been developed.

Asymmetric Organocatalytic Syntheses of Bioactive Compounds

2021 ◽  
Vol 18 ◽  
Author(s):  
Estibaliz Sansinenea ◽  
Aurelio Ortiz
Keyword(s):  
Natural Products ◽  
Asymmetric Synthesis ◽  
Bioactive Compounds ◽  
Cascade Reactions ◽  
Biologically Active ◽  
Active Compounds ◽  
Total Syntheses ◽  
Main Structure ◽  
New Methodologies ◽  
High Stereoselectivity

Background: The total syntheses of complex natural products have evolved to include new methodologies to save time, simplifying the form to achieve these natural compounds. Objective: In this review, we have described the asymmetric synthesis of different natural products and biologically active compounds of the last ten years until the current day. Results: An asymmetric organocatalytic reaction is the key to generate stereoselectively the main structure with the required stereochemistry. Conclusion: Even more remarkable, the organocatalytic cascade reactions, which are carried out with high stereoselectivity, as well as a possible approximation of the organocatalysts activation with substrates are also described.

Sign in / Sign up

Export Citation Format

Share Document