scholarly journals Concise total syntheses of (–)-jorunnamycin A and (–)-jorumycin enabled by asymmetric catalysis

Science ◽  
2018 ◽  
Vol 363 (6424) ◽  
pp. 270-275 ◽  
Author(s):  
Eric R. Welin ◽  
Aurapat Ngamnithiporn ◽  
Max Klatte ◽  
Guillaume Lapointe ◽  
Gerit M. Pototschnig ◽  
...  
Keyword(s):  
Natural Products ◽  
Asymmetric Catalysis ◽  
High Efficiency ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Polycyclic Compounds ◽  
Gram Negative ◽  
Total Syntheses ◽  
Bond Forming ◽  
The Past

The bis-tetrahydroisoquinoline (bis-THIQ) natural products have been studied intensively over the past four decades for their exceptionally potent anticancer activity, in addition to strong Gram-positive and Gram-negative antibiotic character. Synthetic strategies toward these complex polycyclic compounds have relied heavily on electrophilic aromatic chemistry, such as the Pictet–Spengler reaction, that mimics their biosynthetic pathways. Herein, we report an approach to two bis-THIQ natural products, jorunnamycin A and jorumycin, that instead harnesses the power of modern transition-metal catalysis for the three major bond-forming events and proceeds with high efficiency (15 and 16 steps, respectively). By breaking from biomimicry, this strategy allows for the preparation of a more diverse set of nonnatural analogs.

scholarly journals Last Decade of Unconventional Methodologies for the Synthesis of Substituted Benzofurans

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2327 ◽  
Author(s):  
Lucia Chiummiento ◽  
Rosarita D’Orsi ◽  
Maria Funicello ◽  
Paolo Lupattelli
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Intramolecular Cyclization ◽  
Bond Formation ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Metal Free ◽  
Bond Forming ◽  
Intermolecular Cyclization

This review describes the progress of the last decade on the synthesis of substituted benzofurans, which are useful scaffolds for the synthesis of numerous natural products and pharmaceuticals. In particular, new intramolecular and intermolecular C–C and/or C–O bond-forming processes, with transition-metal catalysis or metal-free are summarized. (1) Introduction. (2) Ring generation via intramolecular cyclization. (2.1) C7a–O bond formation: (route a). (2.2) O–C2 bond formation: (route b). (2.3) C2–C3 bond formation: (route c). (2.4) C3–C3a bond formation: (route d). (3) Ring generation via intermolecular cyclization. (3.1) C7a-O and C3–C3a bond formation (route a + d). (3.2) O–C2 and C2–C3 bond formation: (route b + c). (3.3) O–C2 and C3–C3a bond formation: (route b + d). (4) Benzannulation. (5) Conclusion.

scholarly journals Unified divergent strategy towards the total synthesis of the three sub-classes of hasubanan alkaloids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guang Li ◽  
Qian Wang ◽  
Jieping Zhu
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Michael Addition ◽  
Total Syntheses ◽  
Bond Forming ◽  
The Past ◽  
Tricyclic Compounds

AbstractElegant asymmetric synthesis of hasubanan alkaloids have been developed over the past decades. However, a divergent approach leading to all three sub-classes of this family of natural products remains unknown. We report herein the realization of such an endeavor by accomplishing enantioselective total syntheses of four representative members. The synthesis is characterized by catalytic enantioselective construction of the tricyclic compounds from which three different intramolecular C-N bond forming processes leading to three topologically different hasubanan alkaloids are developed. An aza-Michael addition is used for the construction of the aza-[4.4.3]-propellane structure of (-)-cepharamine, whereas an oxidation/double deprotection/intramolecular hemiaminal forming sequence is developed to forge the bridged 6/6/6/6 tetracycle of (-)-cepharatines A and C and a domino bromination/double deprotection/cyclization sequence allows the build-up of the 6/6/5/5 fused tetracyclic structure of (−)-sinoracutine.

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.

The C–H functionalization of N-alkoxycarbamoyl indoles by transition metal catalysis

2021 ◽  
Vol 19 (37) ◽  
pp. 7949-7969
Author(s):  
Prasanjit Ghosh ◽  
Sajal Das
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Indole and its congeners are ubiquitous nitrogen containing organic scaffolds found in a plethora of natural products. This review aims to highlight the transition-metal catalyzed C–H functionalization of N-alkoxycarbamoyl indoles.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

2018 ◽  
Vol 47 (21) ◽  
pp. 8030-8056 ◽  
Author(s):  
Hiroshi Takikawa ◽  
Arata Nishii ◽  
Takahiro Sakai ◽  
Keisuke Suzuki
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Polycyclic Compounds ◽  
Total Syntheses ◽  
Naturally Occurring

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

Metalorganocatalysis: cooperating transition-metal catalysis and organocatalysis through a covalent bond

2015 ◽  
Vol 2 (10) ◽  
pp. 1425-1431 ◽  
Author(s):  
Xiu-Qin Dong ◽  
Qingyang Zhao ◽  
Pan Li ◽  
Caiyou Chen ◽  
Xumu Zhang
Keyword(s):  
Transition Metal ◽  
Asymmetric Catalysis ◽  
Covalent Bond ◽  
Transition Metal Catalysis ◽  
Considerable Progress ◽  
Metal Catalysis

Asymmetric catalysis has grown rapidly and made considerable progress in the last few decades, but there still remain significantly unachievable reactions through either organocatalysis or transition-metal catalysis alone.

Privileged chiral N-heterocyclic carbene ligands for asymmetric transition-metal catalysis

2017 ◽  
Vol 46 (16) ◽  
pp. 4845-4854 ◽  
Author(s):  
Daniel Janssen-Müller ◽  
Christoph Schlepphorst ◽  
Frank Glorius
Keyword(s):  
Transition Metal ◽  
Asymmetric Catalysis ◽  
Transition Metal Catalysis ◽  
Carbene Ligands ◽  
Metal Catalysis

An overview on the most successful chiral N-heterocyclic carbene ligands in asymmetric catalysis is given.

scholarly journals Bond Forming Reactions Involving Isocyanides at Diiron Complexes

Inorganics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 25 ◽  
Author(s):  
Rita Mazzoni ◽  
Fabio Marchetti ◽  
Andrea Cingolani ◽  
Valerio Zanotti
Keyword(s):  
Transition Metal Catalysis ◽  
Organometallic Complexes ◽  
The Other ◽  
Coupling Reactions ◽  
Molecular Fragments ◽  
Carbene Ligands ◽  
Metal Catalysis ◽  
Bond Forming ◽  
Environmental Friendly ◽  
Catalyzed Reactions

The versatility of isocyanides (CNR) in organic chemistry has been tremendously enhanced by continuous advancement in transition metal catalysis. On the other hand, the urgent need for new and more sustainable synthetic strategies based on abundant and environmental-friendly metals are shifting the focus towards iron-assisted or iron-catalyzed reactions. Diiron complexes, taking advantage of peculiar activation modes and reaction profiles associated with multisite coordination, have the potential to compensate the lower activity of Fe compared to other transition metals, in order to activate CNR ligands. A number of reactions reported in the literature shows that diiron organometallic complexes can effectively assist and promote most of the “classic” isocyanide transformations, including CNR conversion into carbyne and carbene ligands, CNR insertion, and coupling reactions with other active molecular fragments in a cascade sequence. The aim is to evidence the potential offered by diiron coordination of isocyanides for the development of new and more sustainable synthetic strategies for the construction of complex molecular architectures.

Synthesis of natural products and analogs using multiple Pd-catalyzed transformations

2007 ◽  
Vol 79 (4) ◽  
pp. 629-650 ◽  
Author(s):  
Lutz F. Tietze ◽  
Tom Kinzel
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Vitamin E ◽  
Relative Stability ◽  
Chiral Ligands ◽  
Heck Reactions ◽  
Vast Number ◽  
Total Syntheses ◽  
Bond Forming ◽  
Palladium Catalyzed

Palladium-catalyzed transformations are of great importance in modern synthetic organic chemistry. The vast number of reactions that can be catalyzed by Pd0- as well as Pd2+-complexes in combination with the relative stability of the intermediates offers the intriguing opportunity of carrying out multiple consecutive bond-forming processes. They can be even performed in a domino fashion and in the presence of chiral ligands to allow the efficient preparation of almost enantiopure compounds. In this article, the use of double Heck, Tsuji-Trost-Heck, and Wacker-Heck reactions for the total syntheses of estradiol, spinosyn A analogs, cephalotaxine, and vitamin E is described.

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