scholarly journals Intramolecular cascade annulation triggered by rhodium(III)-catalyzed sequential C(sp2)–H activation and C(sp3)–H amination

2019 ◽  
Vol 15 ◽  
pp. 571-576 ◽  
Author(s):  
Liangliang Song ◽  
Guilong Tian ◽  
Johan Van der Eycken ◽  
Erik V Van der Eycken
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
The Core

A rhodium(III)-catalyzed intramolecular oxidative annulation of O-substituted N-hydroxyacrylamides for the construction of indolizinones via sequential C(sp2)–H activation and C(sp3)–H amination has been developed. This approach shows excellent functional-group tolerance. The synthesized scaffold forms the core of many natural products with pharmacological relevance.

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

Asymmetric Hydrogenation of O-/N-Functional Group Substituted Arenes

2021 ◽  
Author(s):  
bingru shao ◽  
Lei Shi ◽  
Yong-Gui Zhou
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Asymmetric Hydrogenation ◽  
Biologically Active ◽  
Synthetic Methods

Asymmetric hydrogenation of aromatical compouds represents one of the most straightforward synthetic methods to construct important chiral cyclic skeletons that are often found in biologically active agents and natural products....

scholarly journals Preparation of Cyclic Peptide Alkaloids Containing Functionalized Tryptophan Residues

2006 ◽  
Vol 1 (10) ◽  
pp. 1934578X0600101
Author(s):  
Alexander K. L. Yuen ◽  
Craig A. Hutton
Keyword(s):  
Natural Products ◽  
Cyclic Peptide ◽  
The Novel ◽  
Diazonamide A ◽  
The Core ◽  
Tryptophan Residues ◽  
Novel Methods

This review covers the synthesis of various cyclic peptide natural products possessing highly functionalized tryptophan residues, focusing on the examples of diazonamide A, the TMC-95 compounds, the celogentin/moroidin family and the complestatin/chloropeptin system. Recent efforts toward the preparation of these modified-tryptophan-containing peptides will be outlined, focusing primarily on the novel methods for the assembly of the highly functionalized indole/tryptophan moieties at the core of these structures.

scholarly journals Nickel-Catalyzed Three-Component Olefin Reductive Dicarbofunctionalization to Access Highly Functionalized Alkylborates

2020 ◽  
Author(s):  
Xiao-Xu Wang ◽  
Xi Lu ◽  
Shi-Jiang He ◽  
Yao Fu
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Functional Group ◽  
Coupling Efficiency ◽  
Convergent Synthesis ◽  
Drug Molecules ◽  
Aryl Iodides ◽  
Alkyl Bromides ◽  
Vinyl Boronates ◽  
Convenient Access

We report a three-component olefin reductive dicarbofunctionalization for constructing densely functionalized alkylborates, specifically, nickel-catalyzed reductive dialkylation and alkylarylation of vinyl boronates with a variety of alkyl bromides and aryl iodides. This reaction exhibits good coupling efficiency and excellent functional group compatibility, providing convenient access to the late-stage modification of complex natural products and drug molecules. Combined with versatile alkylborate transformations, this reaction could also find applications in the modular and convergent synthesis of complex, densely functionalized compounds.

scholarly journals Total Syntheses of Marrubiin and Related Labdane Diterpene Lactones

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1610
Author(s):  
Yukari Sakagami ◽  
Naoki Kondo ◽  
Yuki Sawayama ◽  
Hiroyuki Yamakoshi ◽  
Seiichi Nakamura
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Lactone Ring ◽  
Side Chain ◽  
Total Syntheses ◽  
Epoxide Opening ◽  
Labdane Diterpene

Total syntheses of the labdane diterpene lactones marrubiin, marrulibacetal, desertine, marrulibacetal A, marrubasch F, cyllenine C, marrulanic acid, and marrulactone are described. The trans-decalin moiety of these molecules was constructed in a stereoselective manner by a Pauson-Khand reaction, and the resultant cyclopentenone was oxidatively cleaved for formation of the lactone ring. Elongation of the side chain at C9 was achieved by an epoxide-opening reaction with a variety of nucleophiles, and the functional group manipulations completed the syntheses of these natural products. Stereochemistries of desertine could be established by the transformations.

scholarly journals Recent Advances in Organocatalyzed Asymmetric Synthesis of Benzopyran and Benzodihydropyran (Chromane) Nuclei

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1510
Author(s):  
Renato Dalpozzo ◽  
Raffaella Mancuso
Keyword(s):  
Natural Products ◽  
Asymmetric Synthesis ◽  
Organic Synthesis ◽  
Building Blocks ◽  
Core Structure ◽  
The Core ◽  
Recent Advances ◽  
Set Up

Benzopyran and benzodihydropyran (chromane) nuclei are the core structure of many natural products, in particular flavonoids. Many compounds possessing this structure are nutraceuticals, pharmaceutical nutrients. Therefore, benzopyran and chromane scaffolds are important building blocks in organic synthesis and many efforts have been made to set up efficient methods for their synthesis. In particular, asymmetric methods are of great importance, being natural products, and generally chiral substances. This review aims to cover literature in the range 2017–first half of 2019.

scholarly journals Tyrosine and Drug-like Late-stage Benzylic Functionalization via Photoredox Catalysis

2020 ◽  
Author(s):  
Tobias Brandhofer ◽  
Volker Derdau ◽  
María Mendez ◽  
Christoph Pöverlein ◽  
Olga Garcia Mancheno
Keyword(s):  
Natural Products ◽  
Visible Light ◽  
Late Stage ◽  
Medicinal Chemistry ◽  
Functional Group ◽  
Reaction Conditions ◽  
Site Selectivity ◽  
Wide Range ◽  
High Yields ◽  
Therapeutic Compounds

Abstract Visible light mediated late-stage functionalization is a rising field in synthetic and medicinal chemistry, allowing the fast and diversified modification of valuable, potentially therapeutic compounds such as peptides. However, there are relatively few mild methodologies for the C(sp3)-H functionalization of complex peptides. Herein, we report a visible light mediated photocatalytic protocol for the benzylic C-H modification of tyrosine and related C-H bonds. The embraced radical-cation/deprotonation strategy enables an incorporation of a wide range of valuable functional groups in high yields and chemoselectivity. The mild reaction conditions, site-selectivity and high functional group tolerance was highlighted by the functionalization of complex peptides, drugs and natural products, providing a promising synthetic platform in medicinal chemistry.

scholarly journals Co-Catalyzed E-(β)-Selective Hydrogermylation of Terminal Alkynes

2021 ◽  
Author(s):  
Maxim Radzhabov ◽  
Neal Mankad
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Functional Group ◽  
Terminal Alkynes ◽  
Mechanistic Studies ◽  
Practical Utility ◽  
Π Complex ◽  
Accessible Method ◽  
High Yields

<a></a><a>We demonstrated unprecedentedly that Co complexes can catalyze hydrogermylation of alkynes. Subsequently, a selective, accessible method was developed to synthesize E-(β)-vinyl(trialkyl)germanes from various terminal alkynes with high yields. As shown on multiple examples, the developed method demonstrates broad functional group tolerance and practical utility for late-stage hydrogermylation of drugs and natural products. The method is compatible with alkynes bearing both aryl and alkyl substituents, providing unrivaled selectivity for previously challenging 1° alkyl-substituted alkynes. Moreover, the catalyst used in this method, Co<sub>2</sub>(CO)<sub>8</sub>, is a cheap and commercially available reagent. Conducted mechanistic studies supported syn-addition of Bu<sub>3</sub>GeH to an alkyne</a> π-complex.

scholarly journals Enantioselective Access to Dialkyl Amines and Alcohols via Ni-Catalyzed Reductive Hydroalkylations

2021 ◽  
Author(s):  
Shan Wang ◽  
Tian-Yi Zhang ◽  
Jian-Xin Zhang ◽  
Huan Meng ◽  
Bi-Hong Chen ◽  
...  
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Alkyl Halides ◽  
Aliphatic Amines ◽  
Fine Chemicals ◽  
Alkyl Groups ◽  
Simple Protocol ◽  
Enol Esters

Abstract Chiral dialkyl amines and alcohols are ubiquitous in pharmaceuticals, pesticides, natural products and fine chemicals, yet difficult to access due to the challenge to differentiate between the spatially and electronically similar alkyl groups. Herein, we report a nickel-catalyzed enantioselective reductive hydroalkylation of acyl enamines and enol esters with alkyl halides to afford enantioenriched α-branched aliphatic amines and alcohols in good yields with excellent levels of enantioselectivity. The operationally simple protocol provides a straightforward access to chiral dialkyl amine and alcohol derivatives from simple starting materials with great functional group tolerance.

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