Catalytic, Enantioselective α-Alkylation of Azlactones with Non-Conjugated Alkenes via Directed Nucleopalladation

2018 ◽  
Author(s):  
Sri Nimmagadda ◽  
Mingyu Liu ◽  
Malkanthi Karunananda ◽  
De-Wei Gao ◽  
Omar Apolinar ◽  
...  
Keyword(s):  
Amino Acid ◽  
Phosphoric Acid ◽  
Catalytic Cycle ◽  
Amino Acid Derivatives ◽  
Optimal Conditions ◽  
Wide Range ◽  
Directing Group ◽  
High Yields

A palladium(II)-catalyzed enantioselective α-alkylation of azlactones with non-conjugated alkenes is described. The reaction employs a chiral BINOL-derived phosphoric acid as the source of stereoinduction and a cleavable bidentate directing group appended to the alkene to control regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of azlactones were found to be compatible under the optimal conditions to afford products bearing α,α-disubstituted α-amino acid derivatives with high yields and high enantioselectivity.

Catalytic, Enantioselective α-Alkylation of Azlactones with Non-Conjugated Alkenes via Directed Nucleopalladation

2018 ◽  
Author(s):  
Sri Nimmagadda ◽  
Mingyu Liu ◽  
Malkanthi Karunananda ◽  
De-Wei Gao ◽  
Omar Apolinar ◽  
...  
Keyword(s):  
Amino Acid ◽  
Phosphoric Acid ◽  
Catalytic Cycle ◽  
Amino Acid Derivatives ◽  
Optimal Conditions ◽  
Wide Range ◽  
Directing Group ◽  
High Yields

A palladium(II)-catalyzed enantioselective α-alkylation of azlactones with non-conjugated alkenes is described. The reaction employs a chiral BINOL-derived phosphoric acid as the source of stereoinduction and a cleavable bidentate directing group appended to the alkene to control regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of azlactones were found to be compatible under the optimal conditions to afford products bearing α,α-disubstituted α-amino acid derivatives with high yields and high enantioselectivity.

Enantioselective synthesis of cyclic quaternary α-amino acid derivatives by chiral phosphoric acid catalysis

2017 ◽  
Vol 15 (28) ◽  
pp. 6033-6041 ◽  
Author(s):  
Lei Wang ◽  
Abdul Rahman ◽  
Xufeng Lin
Keyword(s):  
Amino Acid ◽  
Phosphoric Acid ◽  
Acid Catalysis ◽  
Enantioselective Synthesis ◽  
Amino Acid Derivatives ◽  
Chiral Phosphoric Acid ◽  
Efficient Route ◽  
Quaternary Stereocenter ◽  
High Yields ◽  
Phosphoric Acids

Development of highly enantioselective aza-Friedel–Crafts reaction of N-sulfonyl cyclic ketimines with indoles catalyzed by chiral phosphoric acids, providing an efficient route to indole-containing chiral cyclic α-amino acid derivatives bearing quaternary stereocenter in high yields and up to 98% enantioselectivity.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis

2019 ◽  
Author(s):  
Andrew Romine ◽  
Kin Yang ◽  
Malkanthi Karunananda ◽  
Jason Chen ◽  
Keary Engle
Keyword(s):  
Mechanistic Studies ◽  
Salvianolic Acid ◽  
Wide Range ◽  
Computational Data ◽  
Synthetic Utility ◽  
Directing Group ◽  
High Yields ◽  
Julia Olefination ◽  
Reaction Progress Kinetic Analysis

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.

UV-Light-Induced Dehydrogenative N-Acylation of Amines with 2-Nitrobenzaldehydes to Give 2-Aminobenzamides

Synthesis ◽  
2022 ◽  
Author(s):  
Dishu Zeng ◽  
Tianbao Yang ◽  
Niu Tang ◽  
Wei Deng ◽  
Jiannan Xiang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Building Block ◽  
Room Temperature ◽  
Uv Light ◽  
Amino Acid Derivatives ◽  
One Pot ◽  
Plausible Mechanism ◽  
High Yields

A simple, mild, green and efficient method for the synthesis of 2-aminobenzamides was highly desired in organic synthesis. Herein, we developed an efficient, one-pot strategy for the synthesis of 2-aminobenzamides with high yields irradiated by UV light. 32 examples proceeded successfully by this photo-induced protocol. The yield reached up to 92%. The gram scale was also achieved easily. This building block could be applied in the preparation of quinazolinones derivatives. Amino acid derivatives could be employed smoothly at room temperature. Finally, a plausible mechanism was proposed.

scholarly journals Applications of tert-butanesulfinamide in the asymmetric synthesis of amines

2003 ◽  
Vol 75 (1) ◽  
pp. 39-46 ◽  
Author(s):  
J. A. Ellman
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Nucleophilic Addition ◽  
Amino Alcohols ◽  
Wide Range ◽  
Aldehydes And Ketones ◽  
Directing Group ◽  
High Yields ◽  
Direct Condensation

tert-Butanesulfinamide is prepared using catalytic enantioselective methods in two steps from the extremely inexpensive oil waste by-product, tert-butyl disulfide. Direct condensation of tert-butanesulfinamide with aldehydes and ketones provides tert-butanesulfinyl imines in uniformly high yields. The tert-butanesulfinyl group activates the imines for the addition of many different classes of nucleophiles, serves as a powerful chiral directing group, and after nucleophilic addition is readily cleaved by treatment with acid. A wide range of highly enantioenriched amines, including α-branched and α,α-dibranched amines, α- and β-amino acids, 1,2 and 1,3-amino alcohols and α-trifluoromethyl amines are efficiently synthesized using this methodology.

scholarly journals Directed, Nickel-Catalyzed Umpolung 1,2-Carboamination of Alkenyl Carbonyl Compounds

2018 ◽  
Author(s):  
Vincent van der Puyl ◽  
Joseph Derosa ◽  
Keary Engle
Keyword(s):  
Amino Acid ◽  
Tertiary Amine ◽  
Carbonyl Compounds ◽  
Amino Acid Derivatives ◽  
Quaternary Carbon ◽  
Carbon Centers ◽  
Two Component ◽  
Directing Group

We report a regioselective, nickel-catalyzed <i>syn</i>-1,2-carboamination of non-conjugated alkenyl carbonyl compounds with <i>O</i>-benzoyl hydroxylamine (N–O) electrophiles and aryl/alkylzinc nucleophiles to afford β- and γ-amino acid derivatives. This method enables preparation of products containing structurally diverse tertiary amine motifs, including heterocycles, and can also be used to form quaternary carbon centers. The reaction takes advantage of a tethered 8-aminoquinoline directing group to control the regiochemical outcome and suppress two-component coupling between the N–O electrophile and organozinc nucleophile.

scholarly journals Biomimetic enantioselective synthesis of β,β-difluoro-α-amino acid derivatives

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Qiupeng Peng ◽  
Bingjia Yan ◽  
Fangyi Li ◽  
Ming Lang ◽  
Bei Zhang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Structural Diversity ◽  
Enantioselective Synthesis ◽  
Amino Acid Derivatives ◽  
Proton Shift ◽  
Wide Range ◽  
Fluorine Compounds ◽  
Optically Pure ◽  
High Stereoselectivity ◽  
High Application

AbstractAlthough utilization of fluorine compounds has a long history, synthesis of chiral fluorinated amino acid derivatives with structural diversity and high stereoselectivity is still very appealing and challenging. Here, we report a biomimetic study of enantioselective [1,3]-proton shift of β,β-difluoro-α-imine amides catalyzed by chiral quinine derivatives. A wide range of corresponding β,β-difluoro-α-amino amides were achieved in good yields with high enantioselectivities. The optically pure β,β-difluoro-α-amino acid derivatives were further obtained, which have high application values in the synthesis of fluoro peptides, fluoro amino alcohols and other valuable fluorine-containing molecules.

scholarly journals Chiral donor–acceptor azetines as powerful reactants for synthesis of amino acid derivatives

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Kostiantyn O. Marichev ◽  
Kuiyong Dong ◽  
Lynée A. Massey ◽  
Yongming Deng ◽  
Luca De Angelis ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Derivatives ◽  
Coupling Reactions ◽  
Central Importance ◽  
Bond Forming ◽  
Donor Acceptor ◽  
High Yields ◽  
High Degree ◽  
Oxygen Bond ◽  
Steric Selectivity

AbstractCoupling reactions of amines and alcohols are of central importance for applications in chemistry and biology. These transformations typically involve the use of a reagent, activated as an electrophile, onto which nucleophile coupling results in the formation of a carbon-nitrogen or a carbon–oxygen bond. Several promising reagents and procedures have been developed to achieve these bond forming processes in high yields with excellent stereocontrol, but few offer direct coupling without the intervention of a catalyst. Herein, we report the synthesis of chiral donor–acceptor azetines by highly enantioselective [3 + 1]-cycloaddition of enoldiazoacetates with aza-ylides and their selective coupling with nitrogen and oxygen nucleophiles via 3-azetidinones to form amino acid derivatives, including those of peptides and natural products. The overall process is general for a broad spectrum of nucleophiles, has a high degree of electronic and steric selectivity, and retains the enantiopurity of the original azetine.

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis

2019 ◽  
Author(s):  
Andrew Romine ◽  
Kin Yang ◽  
Malkanthi Karunananda ◽  
Jason Chen ◽  
Keary Engle
Keyword(s):  
Mechanistic Studies ◽  
Salvianolic Acid ◽  
Wide Range ◽  
Computational Data ◽  
Synthetic Utility ◽  
Directing Group ◽  
High Yields ◽  
Julia Olefination ◽  
Reaction Progress Kinetic Analysis

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.

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