Asymmetric Synthesis of α-Alkylated γ-Lactam via Nickel/8-Quinim-Catalyzed Reductive Alkyl-Carbamoylation of Unactivated Alkene

Synlett ◽  
2021 ◽  
Author(s):  
Xianqing Wu ◽  
Mohini Shrestha ◽  
Yifeng Chen
Keyword(s):  
Functional Group ◽  
Enantioselective Synthesis ◽  
Chiral Auxiliary ◽  
Alkyl Iodide ◽  
General Strategy ◽  
Chemical Bonds ◽  
Mild Conditions ◽  
Chiral Carbon ◽  
Enantioselective Reaction ◽  
Metal Catalyzed

AbstractChiral-auxiliary-mediated synthesis represents the most frequently used synthetic tool for the induction of chirality on α-position of γ-lactams in organic synthesis. However, the general strategy requires the stoichiometric use of chiral reagents with multiple manipulation steps. Transition-metal-catalyzed asymmetric alkene dicarbofunctionalization using readily available substrates under mild conditions allows the simultaneous construction of two vicinal chemical bonds and a chiral carbon center, hence, gain expedient access to chiral heterocycles. Herein, we disclose a Ni-catalyzed enantioselective reaction of 3-butenyl carbamoyl chloride and primary alkyl iodide enabled by a newly designed chiral 8-quinoline imidazoline ligand (8-Quinim). This protocol features broad functional group tolerance and high enantioselectivities, achieving unprecedented synthesis of chiral nonaromatic heterocycles via catalytic reductive protocol.1 Introduction2 Development of 8-Quinim Ligand3 Nickel/8-Quinim-Catalyzed Enantioselective Synthesis of Chiral α-Alkylated γ-Lactam4 Conclusion and Outlook

scholarly journals A General Strategy for the Stereoselective Synthesis of the Furanosesquiterpenes Structurally Related to Pallescensins 1–2

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 245 ◽  
Author(s):  
Stefano Serra
Keyword(s):  
Functional Group ◽  
Stereoselective Synthesis ◽  
Enantioselective Synthesis ◽  
General Strategy ◽  
Chemical Transformations ◽  
High Chemical ◽  
Synthetic Procedure ◽  
Furan Moiety ◽  
Key Steps ◽  
First Time

Here, we describe a general stereoselective synthesis of the marine furanosesquiterpenes structurally related to pallescensins 1–2. The stereoisomeric forms of the pallescensin 1, pallescensin 2, and dihydropallescensin 2 were obtained in high chemical and isomeric purity, whereas isomicrocionin-3 was synthesized for the first time. The sesquiterpene framework was built up by means of the coupling of the C10 cyclogeranyl moiety with the C5 3-(methylene)furan moiety. The key steps of our synthetic procedure are the stereoselective synthesis of four cyclogeraniol isomers, their conversion into the corresponding cyclogeranylsulfonylbenzene derivatives, their alkylation with 3-(chloromethyl)furan, and the final reductive cleavage of the phenylsulfonyl functional group to afford the whole sesquiterpene framework. The enantioselective synthesis of the α-, 3,4-dehydro-γ- and γ-cyclogeraniol isomers was performed using both a lipase-mediated resolution procedure and different regioselective chemical transformations.

scholarly journals Chiral Alkyl Amine Synthesis via Catalytic Enantioselective Hydroalkylation of Enamides

2020 ◽  
Author(s):  
Deyun Qian ◽  
Srikrishna Bera ◽  
Xile Hu
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Building Blocks ◽  
Alkyl Halides ◽  
Enantioselective Synthesis ◽  
Mild Conditions ◽  
Drug Molecules ◽  
Alkyl Amines ◽  
Wide Range ◽  
Synthetic Intermediates

Chiral alkyl amines are omnipresent as bio-active molecules and synthetic intermediates. Catalytic and enantioselective synthesis of alkyl amines from readily accessible precursors is challenging. Here we develop a nickel-catalyzed hydroalkylation method to assemble a wide range of chiral alkyl amines from enamides and alkyl halides in high regio- and enantioselectivity. The method works for both non-activated and activated alkyl halides, and is able to produce enantiomerically enriched amines with two minimally differentiated alpha-alkyl substituents. The mild conditions lead to high functional group tolerance, which is demonstrated in the post-product functionalization of many natural products and drug molecules, as well as the synthesis of chiral building blocks and key intermediates to bio-active compounds.

scholarly journals Chiral Alkyl Amine Synthesis via Catalytic Enantioselective Hydroalkylation of Enamides

2020 ◽  
Author(s):  
Deyun Qian ◽  
Srikrishna Bera ◽  
Xile Hu
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Building Blocks ◽  
Alkyl Halides ◽  
Enantioselective Synthesis ◽  
Mild Conditions ◽  
Drug Molecules ◽  
Alkyl Amines ◽  
Wide Range ◽  
Synthetic Intermediates

Chiral alkyl amines are omnipresent as bio-active molecules and synthetic intermediates. Catalytic and enantioselective synthesis of alkyl amines from readily accessible precursors is challenging. Here we develop a nickel-catalyzed hydroalkylation method to assemble a wide range of chiral alkyl amines from enamides and alkyl halides in high regio- and enantioselectivity. The method works for both non-activated and activated alkyl halides, and is able to produce enantiomerically enriched amines with two minimally differentiated alpha-alkyl substituents. The mild conditions lead to high functional group tolerance, which is demonstrated in the post-product functionalization of many natural products and drug molecules, as well as the synthesis of chiral building blocks and key intermediates to bio-active compounds.

scholarly journals Highly Diastereo- and Enantioselective Synthesis of Quinuclidine Derivatives by an Iridium-Catalyzed Intramolecular Allylic Dearomatization Reaction

CCS Chemistry ◽  
2019 ◽  
pp. 106-116 ◽  
Author(s):  
Lin Huang ◽  
Yue Cai ◽  
Hui-Jun Zhang ◽  
Chao Zheng ◽  
Li-Xin Dai ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Catalytic System ◽  
Density Functional ◽  
Functional Group ◽  
Enantioselective Synthesis ◽  
Large Array ◽  
Functional Theory ◽  
Mild Conditions ◽  
Group Diversity

Asymmetric construction of quinuclidine derivatives has been realized by an iridium-catalyzed allylic dearomatization reaction. The catalytic system, derived from [Ir(cod)Cl] 2 and the Feringa ligand, tolerates a broad range of substrates. A large array of quinuclidine derivatives can be obtained under mild conditions in good to excellent yields (68%–96%), diastereoselectivity (up to >20/1 dr), and enantioselectivity (up to >99% ee). These products feature versatile functional group diversity and can undergo diverse transformations. A model that accounts for the origin of the stereoselectivity has been proposed based on density functional theory (DFT) calculations.

Catalytic Enantioselective Benzylation Directly from Aryl Acetic Acids

2018 ◽  
Author(s):  
Patrick Moon ◽  
Zhongyu Wie ◽  
Rylan Lundgren
Keyword(s):  
Functional Group ◽  
Terminal Event ◽  
Radical Intermediates ◽  
Carbon Carbon Bond ◽  
Or Groups ◽  
Reaction Proceeds ◽  
Wide Availability ◽  
Metal Catalyzed ◽  
The Stability ◽  
Acetic Acids

The stability and wide availability of carboxylic acids make them valuable reagents in chemical synthesis. Most transition metal catalyzed processes using carboxylic acid substrates are initiated by a decarboxylation event that generates reactive carbanion or radical intermediates. Developing enantioselective methodologies relying on these principles can be challenging, as highly reactive species tend to react indiscriminately without selectivity. Furthermore, anionic or radical intermediates generated from decarboxylation can be incompatible with protic and electrophilic functionality, or groups that undergo trapping with radicals. We demonstrate that metal-catalyzed enantioselective benzylation reactions of allylic electrophiles can occur directly from aryl acetic acids. The reaction proceeds via a pathway in which decarboxylation is the terminal event, occurring after stereoselective carbon–carbon bond formation. The mechanistic features of the process enable enantioselective benzylation without the generation of a highly basic nucleophile. Thus, the process has broad functional group compatibility that would not be possible employing established protocols.<br>

Rh (III)-catalyzed C(sp2)-H functionalization/cyclization cascade of N-carboxamide indole and iodonium reagent for access to indoloquinazolinone derivatives

2021 ◽  
Author(s):  
Zhi-Peng Han ◽  
Mengmeng Xu ◽  
Rui-Ying Zhang ◽  
Xiao-Ping Xu ◽  
Shun-Jun Ji
Keyword(s):  
Functional Group ◽  
Mild Conditions

Rhodium-catalyzed synthesis of indoloquinazoline from readily available hypervalent iodonium reagent and N-carboxamide indole was developed. The protocol features broad functional group tolerance, mild conditions, excellent yields and simple workup. Notably,...

scholarly journals Homocoupling of terminal alkynes catalyzed by CuCl under solvent-free conditions

2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  
Keyword(s):  
Functional Group ◽  
Reaction Times ◽  
Environmentally Friendly ◽  
Solvent Free ◽  
Copper Salt ◽  
Terminal Alkynes ◽  
Mild Conditions ◽  
Solvent Free Conditions ◽  
Environmentally Friendly Process

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

Direct and metal-free oxidative amination of sp3 C–H bonds for the construction of 2-hetarylquinazolin-4(3H)-ones

2016 ◽  
Vol 3 (9) ◽  
pp. 1096-1099 ◽  
Author(s):  
Huanhuan Liu ◽  
Tianran Zhai ◽  
Shiteng Ding ◽  
Yalei Hou ◽  
Xiangyu Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
New Method ◽  
Oxidative Amination ◽  
Metal Free ◽  
Mild Conditions

New method for synthesis of 2-hetarylquinazolin-4(3H)-ones from 2-aminobenzamides and (2-azaaryl)methanes under transition-metal free conditions, featuring a wide substrate scope with a broad range of functional group tolerance under mild conditions.

scholarly journals Protecting group-free, selective cross-coupling of alkyltrifluoroborates with borylated aryl bromides via photoredox/nickel dual catalysis

2015 ◽  
Vol 112 (39) ◽  
pp. 12026-12029 ◽  
Author(s):  
Yohei Yamashita ◽  
John C. Tellis ◽  
Gary A. Molander
Keyword(s):  
Small Molecules ◽  
Functional Group ◽  
Cross Coupling ◽  
Differential Protection ◽  
Coupling Reactions ◽  
Protecting Group ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Rapid Construction ◽  
Metal Catalyzed

Orthogonal reactivity modes offer substantial opportunities for rapid construction of complex small molecules. However, most strategies for imparting orthogonality to cross-coupling reactions rely on differential protection of reactive sites, greatly reducing both atom and step economies. Reported here is a strategy for orthogonal cross-coupling wherein a mechanistically distinct activation mode for transmetalation of sp3-hybridized organoboron reagents enables C-C bond formation in the presence of various protected and unprotected sp2-hybridized organoborons. This manifold has the potential for broad application, because orthogonality is inherent to the activation mode itself. The diversification potential of this platform is shown in the rapid elaboration of a trifunctional lynchpin through various transition metal-catalyzed processes without nonproductive deprotection or functional group manipulation steps.

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