scholarly journals Late-Stage Terpene Cyclization by an Integral Membrane Cyclase in the Biosynthesis of Isoprenoid Epoxycyclohexenone Natural Products

2017 ◽  
Vol 19 (19) ◽  
pp. 5376-5379 ◽  
Author(s):  
Man-Cheng Tang ◽  
Xiaoqing Cui ◽  
Xueqian He ◽  
Zhuang Ding ◽  
Tianjiao Zhu ◽  
...  
Keyword(s):  
Natural Products ◽  
Late Stage

Synthesis of Spongidine A, D and Petrosaspongiolide L Methyl Ester Using Pyridine C-H Functionalization

2019 ◽  
Author(s):  
Florian Bartels ◽  
Manuela Weber ◽  
Mathias Christmann
Keyword(s):  
Natural Products ◽  
Methyl Ester ◽  
Hydrogen Atom ◽  
Phospholipase A2 ◽  
Late Stage ◽  
Hydrogen Atom Transfer ◽  
Ring System ◽  
Tetracyclic Core ◽  
Intramolecular Hydrogen ◽  
Phospholipase A2 Inhibitors

<div>An efficient strategy for the synthesis of the potent phospholipase A2 inhibitors spongidine A and D is presented. The tetracyclic core of the natural products was assembled via an intramolecular hydrogen atom transfer‐initiated Minisci reaction. A divergent late‐stage functionalization of the tetracyclic ring system was also used to achieve a concise synthesis of petrosaspongiolide L methyl ester.</div>

scholarly journals Mechanically induced solvent-free esterification method at room temperature

RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 5080-5085
Author(s):  
Lei Zheng ◽  
Chen Sun ◽  
Wenhao Xu ◽  
Alexandr V. Dushkin ◽  
Nikolay Polyakov ◽  
...  
Keyword(s):  
Natural Products ◽  
Carboxylic Acids ◽  
Late Stage ◽  
Reaction Mechanisms ◽  
Room Temperature ◽  
Solvent Free ◽  
Mild Conditions

We have developed I2/KH2PO2 and KI/P(OEt)3 strategy syntheses of esters from carboxylic acids and alcohols through different reaction mechanisms. The advantages of present protocol: mild conditions and late-stage diversification of natural products.

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.

Diversified synthesis and α-selective glycosylation of 3-amino-2,3,6-trideoxy sugars

2018 ◽  
Vol 5 (23) ◽  
pp. 3391-3395 ◽  
Author(s):  
Jing Zeng ◽  
Ruobin Wang ◽  
Wang Yao ◽  
Shuxin Zhang ◽  
Guangfei Sun ◽  
...  
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Bioactive Natural Products

Quick access to various unnatural 3-amino-2,3,6-trideoxy sugars was achieved by sequential functionalization of a glycal intermediate. This strategy and the further glycosylation method allowed the efficient late-stage modification of bioactive natural products and drugs.

scholarly journals Dehydration reactions in polyfunctional natural products

2020 ◽  
Vol 37 (8) ◽  
pp. 1043-1064
Author(s):  
Per Hjerrild ◽  
Thomas Tørring ◽  
Thomas B. Poulsen
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Dehydration Reactions ◽  
Chemical Dehydration ◽  
Molecular Substrates

Here, we review methods for chemical dehydration of alcohols to alkenes and discuss the potential of late-stage functionalization by direct, site- and chemo-selective dehydration of complex molecular substrates.

Synthetic approaches to [5,6]-benzannulated spiroketal natural products

2011 ◽  
Vol 84 (6) ◽  
pp. 1379-1390 ◽  
Author(s):  
Michael C. McLeod ◽  
Margaret A. Brimble ◽  
Dominea C. K. Rathwell ◽  
Zoe E. Wilson ◽  
Tsz-Ying Yuen
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Electronic Properties ◽  
Late Stage ◽  
Biologically Active ◽  
Formal Synthesis ◽  
Berkelic Acid ◽  
Synthetic Approaches

Studies toward the synthesis of three biologically active [5,6]-benzannulated spiroketal natural products are described. The first total synthesis of paecilospirone is reported, employing a late-stage, pH-neutral spiroketalization. A formal synthesis of γ-rubromycin is described, where the spiroketal moiety is formed by delicate manipulation of the electronic properties of the spirocyclization precursor. Finally, model work toward the total synthesis of berkelic acid is summarized, introducing a novel Horner–Wadsworth–Emmons/oxa-Michael (HWE/oxa-M) cascade to access the spiroketal precursor.

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.

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