scholarly journals Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

2021 ◽  
Vol 17 ◽  
pp. 2668-2679
Author(s):  
Ilya A P Jourjine ◽  
Lukas Zeisel ◽  
Jürgen Krauß ◽  
Franz Bracher
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Functional Groups ◽  
Oxidative Cyclization ◽  
Metal Free ◽  
Dehydrogenative Coupling ◽  
Protective Groups

Highly substituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone.

Facile synthesis of 3-amino-5-aryl-1,2,4-oxadiazoles via PIDA-mediated intramolecular oxidative cyclization

RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54277-54280 ◽  
Author(s):  
Kuan Lu ◽  
Liancheng Duan ◽  
Boxuan Xu ◽  
Weile Yin ◽  
Di Wu ◽  
...  
Keyword(s):  
Functional Groups ◽  
Simple Procedure ◽  
Oxidative Cyclization ◽  
Ambient Condition ◽  
Facile Synthesis ◽  
Metal Free ◽  
Intramolecular Oxidative Cyclization

Advantages: ambient condition and simple procedure. Additive and metal free method. Up to 25 examples and 79% yield. Wide functional groups tolerance.

A transition metal-free approach to a regioselective total synthesis of the natural product derivative 6-methylellipticine, a potent anticancer agent

2019 ◽  
Vol 60 (51) ◽  
pp. 151309 ◽  
Author(s):  
Song-Bo Lin ◽  
Wan-Wan Wang ◽  
Jin-Peng Meng ◽  
Xi-Wang Li ◽  
Jun Wu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Total Synthesis ◽  
Natural Product ◽  
Anticancer Agent ◽  
Metal Free

Formal Total Synthesis of (±)-Rhazinal: Evaluating the Radical Approach

Synthesis ◽  
2017 ◽  
Vol 49 (11) ◽  
pp. 2584-2588 ◽  
Author(s):  
Sven Hildebrandt ◽  
Hendrik Weißbarth ◽  
Andreas Gansäuer
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Functional Groups ◽  
Radical Approach

We describe a formal total synthesis of the racemic natural product rhazinal by a rapid elaboration of a recently reported tetrahydroindolizine intermediate into the cyclization precursor reported by Trauner. The synthesis focuses on the early and convergent introduction of functional groups while the synthetic challenges encountered by this approach are described.

A New Protocol for Total Synthesis of Natural Product Frutinone A and Its Derivatives

2016 ◽  
Vol 69 (1) ◽  
pp. 98 ◽  
Author(s):  
Kang Lei ◽  
Dong-Wei Sun ◽  
Yuan-Yuan Tao ◽  
Xiao-Hua Xu
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Good Yield ◽  
Substitution Reaction ◽  
High Tolerance ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free ◽  
Intramolecular Nucleophilic Substitution

A new protocol for total synthesis of natural product frutinone A was accomplished in three steps by using inexpensive 2′-hydroxyacetophenone as starting material. The key intermediate 3-(2-chlorobenzoyl)-4-hydroxycoumarin was synthesized in one pot through Baker–Venkataraman rearrangement of 2-acetylphenyl 2-chlorobenzoate followed by introduction of methyl chloroformate under basic conditions. Then, base-promoted intramolecular nucleophilic substitution reaction of 3-(2-chlorobenzoyl)-4-hydroxycoumarin provided frutinone A in excellent yield. The synthetic route features good yield, transition metal-free and mild reaction conditions, and high tolerance for functionality, thereby allowing easy substitutions around the frutinone A core.

Synthesis of (+)-bovidic acid

2015 ◽  
Vol 93 (2) ◽  
pp. 196-198 ◽  
Author(s):  
Geoffrey A. Phillips ◽  
Timothy B. Wright ◽  
Andrew C. Stevens ◽  
Brian L. Pagenkopf
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Second Generation ◽  
Oxidative Cyclization ◽  
The Core ◽  
Insect Repellant

(+)-Bovidic acid is an 18-carbon hydroxyfuranoid acid isolated from the pelage of the gaur (Bos frontalis) and displays potential as an insect repellant. Both a formal and total synthesis of (+)-bovidic acid was carried out with the core of the natural product being synthesized through Mukaiyama aerobic oxidative cyclization employing the second-generation Co(nmp)2 catalyst.

Tiacumicin B: An Antibiotic of Prime Importance and a Natural Product with an Inspiring Complex Structure

Synthesis ◽  
2018 ◽  
Vol 50 (21) ◽  
pp. 4189-4200 ◽  
Author(s):  
Emmanuel Roulland
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Complex Structure ◽  
Short Review ◽  
Molecular Structures ◽  
Protective Groups ◽  
Natural Products Synthesis

This short review aims at decrypting and analyzing the various strategies used for the synthesis of tiacumicin B. Natural products synthesis is a way for organic chemists to express inventiveness, intellectual dexterity, and elegance in strategy of synthesis. Some molecular structures are more inspiring than others; and if like tiacumicin B, the architectural challenge meets high biological and medicinal interest, the molecule can then attract the attention of many groups of synthetic chemists.1 Introduction2 The Strategic Challenges of this Total Synthesis3 Construction of the C1–C5 Region4 Construction of the C14–C19 Region5 Construction of the C5–C12 Region6 Construction of the C12–C15 Diene Motif7 Macrocyclization8 Synthesis of the Rhamnosyl Donor9 Synthesis of the Noviosyl Donor and Glycosylation10 The Recurrent Problems Caused by Protective Groups11 Conclusion

scholarly journals DDQ-Promoted Mild and Efficient Metal-Free Oxidative α-Cyanation of N-Acyl/Sulfonyl 1,2,3,4-Tetrahydroisoquinolines

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3223 ◽  
Author(s):  
Hong Kim ◽  
Heesun Yu ◽  
Hyoungsu Kim ◽  
Seok-Ho Kim ◽  
Dongjoo Lee
Keyword(s):  
Total Synthesis ◽  
Ambient Temperature ◽  
Natural Product ◽  
Natural Product Synthesis ◽  
Protecting Groups ◽  
Metal Free ◽  
Wide Range ◽  
Iminium Ions ◽  
Synthetic Utility ◽  
Ddq Oxidation

A mild and highly efficient metal-free oxidative α-cyanation of N-acyl/sulfonyl 1,2,3,4-tetrahydroisoquinolines (THIQs) has been accomplished at an ambient temperature via DDQ oxidation and subsequent trapping of N-acyl/sulfonyl iminium ions with (n-Bu)3SnCN. Employing readily removable N-acyl/sulfonyl groups as protecting groups rather than N-aryl ones enables a wide range of applications in natural product synthesis. The synthetic utility of the method was illustrated using a short and efficient formal total synthesis of (±)-calycotomine in three steps.

Total synthesis of ent-(−)-azonazine using a biomimetic direct oxidative cyclization and structural reassignment of natural product

Tetrahedron ◽  
2014 ◽  
Vol 70 (19) ◽  
pp. 3197-3210 ◽  
Author(s):  
Ji-Chen Zhao ◽  
Shun-Ming Yu ◽  
Hai-Bo Qiu ◽  
Zhu-Jun Yao
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Oxidative Cyclization

scholarly journals Access to 1-indolyltetrahydro-β-carbolines via metal-free cross-dehydrogenative coupling: the total synthesis of eudistomin U, isoeudistomin U and 19-bromoisoeudistomin U

2021 ◽  
Author(s):  
Ganapathy Ranjani ◽  
Rajagopal Nagarajan
Keyword(s):  
Total Synthesis ◽  
Metal Free ◽  
Dehydrogenative Coupling

A highly selective metal-free CDC approach for the synthesis of 1-indolyltetrahydro-β-carbolines is developed. The total synthesis of biologically important alkaloids, eudistomin U and isoeudistomin U and the first total synthesis of 19-bromoisoeudistomin U were accomplished.

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