Lewis Acid-Mediated Efficient Synthesis of 4H-1,3-benzo-xazines and Their Derivatives 4,5-dihydro-1,3-benzo-xazepines

2020 ◽  
Vol 24 (11) ◽  
pp. 1263-1273
Author(s):  
An Junkai ◽  
Liu Jikun ◽  
Shi Ying ◽  
Zhu Weiwei ◽  
Guo Guoying ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Lewis Acid ◽  
Functional Group ◽  
Materials Science ◽  
Pharmaceutical Research ◽  
Direct Access ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Promising Strategy ◽  
Characteristic Features

: Compounds containing 4H-1,3-benzo-xazine core usually possess characteristic features and have been applied in the fields of organic synthesis, pharmaceutical research, materials science and bioscience. Here we reported convenient and direct access to 4H-1,3- benzo-xazines and their derivatives through intramolecular cyclization of olefinic amides or ureas with good to excellent yields in the presence of TMSOTf. The properties (mild conditions, metal or additives-free, wide substrate scope and functional group tolerance) of the process made it a promising strategy to synthesize various benzo-xazines and their derivatives.

scholarly journals Palladium-Catalyzed Cross-Coupling of Gem-Bromofluoroalkenes with Alkylboronic Acids for the Synthesis of Alkylated Monofluoroalkenes

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5532
Author(s):  
Laëtitia Chausset-Boissarie ◽  
Nicolas Cheval ◽  
Christian Rolando
Keyword(s):  
Organic Synthesis ◽  
Functional Group ◽  
Materials Science ◽  
Cross Coupling ◽  
High Yield ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Strategy

Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of gem-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the gem-bromofluoroalkenes geometry.

Bromotrifluoromethane: A Useful Reagent for Hydrotrifluoromethylation of Alkenes and Alkynes

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1028-1032 ◽  
Author(s):  
Xing Zheng ◽  
Xingang Zhang ◽  
Yu-Yan Ren
Keyword(s):  
Visible Light ◽  
Organic Synthesis ◽  
Functional Group ◽  
Mild Conditions ◽  
Industrial Material ◽  
Reaction Proceeds

Bromotrifluoromethane (CF3Br) is a simple, inexpensive and abundant industrial material employed as a trifluoromethylating reagent. However, only limited strategies using CF3Br as a fluorine source are reported. Herein, we describe a visible-light-induced hydrotrifluoromethylation of alkenes and alkynes with CF3Br. The reaction proceeds under mild conditions with good functional group tolerance, providing a new route for the application of BrCF3 in organic synthesis.

scholarly journals Nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts enabled by NN2 pincer ligand

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingjie Zhang ◽  
Di Qi ◽  
Chenchen Jiao ◽  
Xiaopan Liu ◽  
Guisheng Zhang
Keyword(s):  
Functional Group ◽  
High Efficiency ◽  
Materials Science ◽  
Alkylating Agents ◽  
Sonogashira Coupling ◽  
Pincer Ligand ◽  
One Pot ◽  
Mild Conditions ◽  
Alkyl Amines ◽  
Sonogashira Reactions

AbstractAlkynes are amongst the most valuable functional groups in organic chemistry and widely used in chemical biology, pharmacy, and materials science. However, the preparation of alkyl-substituted alkynes still remains elusive. Here, we show a nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts. Key to the success of this coupling is the development of an easily accessible and bench-stable amide-type pincer ligand. This ligand allows naturally abundant alkyl amines as alkylating agents in Sonogashira reactions, and produces diverse alkynes in excellent yields under mild conditions. Salient merits of this chemistry include broad substrate scope and functional group tolerance, gram-scale synthesis, one-pot transformation, versatile late-stage derivatizations as well as the use of inexpensive pre-catalyst and readily available substrates. The high efficiency and strong practicability bode well for the widespread applications of this strategy in constructing functional molecules, materials, and fine chemicals.

scholarly journals Direct Access to Mono-Protected Homoallylic 1,2-Diols via Dual Chromium/ Photoredox Catalysis

2020 ◽  
Author(s):  
Felix Schäfers ◽  
Linda Quach ◽  
J. Luca Schwarz ◽  
Mar Saladrigas ◽  
Constantin G. Daniliuc ◽  
...  
Keyword(s):  
Functional Group ◽  
Protecting Groups ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Efficient Synthesis ◽  
Enol Ethers ◽  
Silyl Enol Ethers

<p>A dual catalytic strategy enables the efficient synthesis of mono-protected homoallylic 1,2-diols by coupling abundant aldehydes with simple (silyl) enol ethers, thus providing direct access to this important motif without the (super)stoichiometric use of prefunctionalized metal-allyl species. A variety of silyl- and alkyl-based protecting groups is shown and functional group tolerance, chemoselectivity and scalability are highlighted. </p>

Efficient Synthesis of Diverse 5-Thio- or 5-Selenotriazoles: One-Pot Multicomponent Reaction from Elemental Sulfur or Selenium

Synthesis ◽  
2019 ◽  
Vol 51 (22) ◽  
pp. 4170-4182 ◽  
Author(s):  
Lin-Lin Zhang ◽  
Ya-Ting Li ◽  
Ting Gao ◽  
Sha-Sha Guo ◽  
Bei Yang ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Functional Group ◽  
High Efficiency ◽  
Efficient Synthesis ◽  
One Pot ◽  
Mild Conditions ◽  
Ligand Free ◽  
Multistep Reaction ◽  
Easy Operation

A sequential multistep reaction toward 5-thio- or 5-selenotriazoles has been established by generation of both copper(I) triazolides and sulfenylating or selenylating agents in situ, starting from elemental sulfur or selenium. This reaction features mild conditions, readily available and broad-scope substrates, good functional group compatibility, high efficiency and regioselectivity, easy operation, and ligand-free CuI.

Ligand- and catalyst-free intramolecular C-S bond formation: direct access to indalothiochromen- 4-ones

2015 ◽  
Vol 21 (3) ◽  
pp. 159-163 ◽  
Author(s):  
T.A. Jenifer Vijay ◽  
Nagarakere C. Sandhya ◽  
C.S. Pavankumar ◽  
Kanchugarakoppal S. Rangappa ◽  
Kempegowda Mantelingu
Keyword(s):  
Functional Group ◽  
Direct Synthesis ◽  
Bond Formation ◽  
Direct Access ◽  
Mild Conditions ◽  
Catalyst Free

AbstractAn efficient ligand- and catalyst-free intramolecular S-arylation leading to the direct synthesis of indalothiochromen-4-ones from simple dithioesters under mild conditions has been developed. This method is particularly noteworthy given its experimental simplicity, high generality, and good functional group toleration.

scholarly journals One-Pot Reductive Acetylation of Aldehydes using 1-Hydrosilatrane in Acetic Acid

SynOpen ◽  
2019 ◽  
Vol 03 (01) ◽  
pp. 1-3 ◽  
Author(s):  
Reuben James ◽  
Sharon Herlugson ◽  
Sami Varjosaari ◽  
Vladislav Skrypai ◽  
Zainab Shakeel ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Organic Synthesis ◽  
Functional Group ◽  
Building Blocks ◽  
Flash Chromatography ◽  
Primary Alcohols ◽  
Facile Synthesis ◽  
One Pot ◽  
Aryl Aldehydes ◽  
Mild Conditions

A one-pot, direct reductive acetylation of aldehydes was achieved under mild conditions using 1-hydrosilatrane as a safe and easily accessible catalyst. Described herein is a facile synthesis that produces acylated primary alcohols that can serve as valuable building blocks for organic synthesis. The method has good functional group tolerance and works for a range of aryl aldehydes, with the notable exception of electron-rich arenes. A library of esters was isolated by flash chromatography in yields as high as 92%.

scholarly journals Direct Access to Mono-Protected Homoallylic 1,2-Diols via Dual Chromium/ Photoredox Catalysis

2020 ◽  
Author(s):  
Felix Schäfers ◽  
Linda Quach ◽  
J. Luca Schwarz ◽  
Mar Saladrigas ◽  
Constantin G. Daniliuc ◽  
...  
Keyword(s):  
Functional Group ◽  
Protecting Groups ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Efficient Synthesis ◽  
Enol Ethers ◽  
Silyl Enol Ethers

<p>A dual catalytic strategy enables the efficient synthesis of mono-protected homoallylic 1,2-diols by coupling abundant aldehydes with simple (silyl) enol ethers, thus providing direct access to this important motif without the (super)stoichiometric use of prefunctionalized metal-allyl species. A variety of silyl- and alkyl-based protecting groups is shown and functional group tolerance, chemoselectivity and scalability are highlighted. </p>

scholarly journals Direct Access to Mono-Protected Homoallylic 1,2-Diols via Dual Chromium/ Photoredox Catalysis

2020 ◽  
Author(s):  
Felix Schäfers ◽  
Linda Quach ◽  
J. Luca Schwarz ◽  
Mar Saladrigas ◽  
Constantin G. Daniliuc ◽  
...  
Keyword(s):  
Functional Group ◽  
Protecting Groups ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Efficient Synthesis ◽  
Enol Ethers ◽  
Silyl Enol Ethers

<p>A dual catalytic strategy enables the efficient synthesis of mono-protected homoallylic 1,2-diols by coupling abundant aldehydes with simple (silyl) enol ethers, thus providing direct access to this important motif without the (super)stoichiometric use of prefunctionalized metal-allyl species. A variety of silyl- and alkyl-based protecting groups is shown and functional group tolerance, chemoselectivity and scalability are highlighted. </p>

scholarly journals (4+3)-Cycloaddition of Donor-Acceptor Cyclopropanes with Thiochalcones: A Diastereoselective Access to Tetrahydrothiepines

2019 ◽  
Author(s):  
André U. Augustin ◽  
J. Luca Merz ◽  
Peter G. Jones ◽  
Grzegorz Mloston ◽  
Daniel Werz
Keyword(s):  
Lewis Acid ◽  
Functional Group ◽  
Cycloaddition Reaction ◽  
Building Blocks ◽  
Mild Conditions ◽  
Donor Acceptor ◽  
Acid Catalyzed ◽  
Sulfur Containing

A general approach is described for the formation of tetrahydrothiepines using donor-acceptor cyclopropanes. Thiochalcones, functioning as sulfur-containing four-atom building blocks, were reacted in a Lewis-acid-catalyzed formal (4+3)-cycloaddition reaction with donor-acceptor cyclopropanes as three-atom building blocks. Under mild conditions various tetrahydrothiepines were synthesized in good yields in a stereosepecific reaction with high functional group tolerance.

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