Anomalies in the Stereoselectivity of the Petasis Reaction Using Styrenyl Boronic Acids

2011 ◽  
Vol 64 (1) ◽  
pp. 62 ◽  
Author(s):  
Quentin I. Churches ◽  
James K. Johnson ◽  
Nathan L. Fifer ◽  
Craig A. Hutton
Keyword(s):  
Glyoxylic Acid ◽  
Coupling Reaction ◽  
Boronic Acids ◽  
High Yield ◽  
Amino Acid Derivatives ◽  
Efficient Synthesis ◽  
Asymmetric Dihydroxylation ◽  
Petasis Reaction ◽  
Efficient Route ◽  
Unsaturated Amino Acid

The Petasis three-component coupling reaction of N-benzylphenylglycinol, glyoxylic acid, and styrenylboronic acids allows for the efficient synthesis of functionalized homoarylalanine derivatives. The reactions were shown to proceed in high yield but low selectivity, regardless of the nature of the substituent on the styrenylboronic acid component. Anomalies in the stereoselectivity of these reactions compared with previously reported results have been traced to the source of the organoboronic acid. Asymmetric dihydroxylation of the unsaturated amino acid derivatives enables a highly efficient route to dihydroxyhomoarylalanine derivatives.

Efficient synthesis of tetrasubstituted 2,3-allenoates and preliminary studies on bioactivities

2019 ◽  
Vol 6 (3) ◽  
pp. 304-308 ◽  
Author(s):  
Yuan Yao ◽  
Guirong Zhu ◽  
Qin Chen ◽  
Hui Qian ◽  
Shengming Ma
Keyword(s):  
Coupling Reaction ◽  
Boronic Acids ◽  
Efficient Synthesis ◽  
Highly Efficient ◽  
Palladium Catalyzed

A general and highly efficient straightforward protocol for the preparation of tetrasubstituted 2,3-allenoates through a palladium-catalyzed coupling reaction of 3-alkoxycarbonyl propargylic carbonates and boronic acids with commercially available tri(o-tolyl)phosphine as a ligand has been developed.

The Synthesis of Fluorescent DNA Intercalator Precursors through Efficient Multiple Heck Reactions

2011 ◽  
Vol 64 (3) ◽  
pp. 316 ◽  
Author(s):  
Nigel A. Lengkeek ◽  
Ramiz A. Boulos ◽  
Allan J. McKinley ◽  
Thomas V. Riley ◽  
Boris Martinac ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Benzene Derivatives ◽  
Efficient Synthesis ◽  
Heck Reactions ◽  
Dna Intercalator ◽  
Highly Efficient ◽  
Cross Coupling Reaction ◽  
Efficient Route

A highly efficient synthesis of p-carboethoxy-tristyryl and carboethoxy-terastyrenyl benzene derivatives through a multiple Heck cross coupling reaction is reported. This reaction provides an efficient route to DNA intercalator precursors containing a benzene core.

scholarly journals Multistep batch-flow hybrid synthesis of a terbinafine precursor

2021 ◽  
Author(s):  
Tamás Hergert ◽  
Béla Mátravölgyi ◽  
Róbert Örkényi ◽  
János Éles ◽  
Ferenc Faigl
Keyword(s):  
Methyl Ether ◽  
Lithium Salt ◽  
Scale Up ◽  
Hybrid Process ◽  
High Yield ◽  
Grignard Reaction ◽  
Efficient Synthesis ◽  
Synthetic Process ◽  
Synthesis Route ◽  
Selective Addition

AbstractA three-step batch-flow hybrid process has been developed for an expeditious synthesis of the enynol key intermediate of antifungal terbinafine. This procedure involves consecutive organometallic steps without the necessity of any in-line purification: after a metalation by n-butyllithium, a selective addition of the lithium salt was elaborated followed by a Grignard reaction resulting in a high yield of 6,6-dimethylhept-1-en-4-yn-3-ol. Moreover, as an alternative to tetrahydrofuran, cyclopentyl methyl ether was used as solvent implementing a safe, sustainable, yet selective synthetic process. Even on a laboratory-scale, the optimized batch-flow hybrid process had a theoretical throughput of 41 g/h. Furthermore, the newly developed process provides an efficient synthesis route to the key-intermediate, while making acrolein obsolete, minimizing side-products, and enabling safe and convenient scale-up.

An Efficient Route to Biaryl Bisbenzocyclobutene Monomers Based on Suzuki Coupling Reaction at Room Temperature.

ChemInform ◽  
2005 ◽  
Vol 36 (38) ◽  
Author(s):  
Jun-xiao Yang ◽  
Kuo-yan Ma ◽  
Fang-hua Zhu ◽  
Wen Chen ◽  
Bo Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Coupling Reaction ◽  
Suzuki Coupling ◽  
Suzuki Coupling Reaction ◽  
Efficient Route

scholarly journals PEG-embedded KBr3: A recyclable catalyst for multicomponent coupling reaction for the efficient synthesis of functionalized piperidines

2011 ◽  
Vol 7 ◽  
pp. 1334-1341 ◽  
Author(s):  
Sanny Verma ◽  
Suman L Jain ◽  
Bir Sain
Keyword(s):  
Coupling Reaction ◽  
Recyclable Catalyst ◽  
Efficient Synthesis ◽  
Molecular Bromine ◽  
Keto Ester ◽  
One Step ◽  
High Yields ◽  
Multicomponent Coupling ◽  
Three Component Coupling

PEG-embedded potassium tribromide ([K+PEG]Br3 −) was found to be an efficient and recyclable catalyst for the synthesis of functionalized piperidines in high yields in a one step, three component coupling between aldehyde, amine and β-keto ester. At the end of the reaction the [K+PEG]Br3 − was readily regenerated from the reaction mixture by treating the residue containing [K+PEG]Br− with molecular bromine.

ChemInform Abstract: Efficient Synthesis of Modular Amino Acid Derivatives Containing Selenium with Pronounced GPx-Like Activity.

ChemInform ◽  
2010 ◽  
Vol 41 (3) ◽  
Author(s):  
Eduardo E. Alberto ◽  
Letiere C. Soares ◽  
Jessie H. Sudati ◽  
Antonio C. A. Borges ◽  
Joao B. T. Rocha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Derivatives ◽  
Efficient Synthesis

Enantioselective synthesis of (R)-tolterodine using lithiation/borylation–protodeboronation methodology

2012 ◽  
Vol 90 (11) ◽  
pp. 965-974 ◽  
Author(s):  
Stefan Roesner ◽  
Varinder K. Aggarwal
Keyword(s):  
Enantioselective Synthesis ◽  
High Yield ◽  
Magnesium Bromide ◽  
Efficient Synthesis ◽  
Boronic Ester ◽  
Better Than

The synthesis of the pharmaceutical (R)-tolterodine is reported using lithiation/borylation–protodeboronation of a homoallyl carbamate as the key step. This step was tested with two permutations: an electron-neutral aryl Li-carbamate reacting with an electron-rich boronic ester and an electron-rich aryl Li-carbamate reacting with an electron-neutral boronic ester. It was found that the latter arrangement was considerably better than the former. Further improvements were achieved using magnesium bromide in methanol leading to a process that gave high yield and high enantioselectivity in the lithiation/borylation reaction. The key step was used in an efficient synthesis of (R)-tolterodine in a total of eight steps in a 30% overall yield and 90% ee.

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