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1.
Org Lett ; 25(17): 3109-3113, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37083288

RESUMO

An electron donor-acceptor (EDA) complex photoactivation strategy for radical fluorosulfonylation is disclosed for the first time. Simply upon blue light irradiation, the FSO2 radical can be generated efficiently under catalyst-free, base-free, and additive-free conditions, which enables facile access to 6-keto alkenylsulfonyl fluorides from readily available propargyl alcohols and FSO2Cl. The 6-keto alkenylsulfonyl fluoride motif has been showcased as a versatile SuFEx hub with diverse follow-up derivatizations.

2.
bioRxiv ; 2023 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-37034579

RESUMO

Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neuron classes in the circuits that generate behavior have a remarkable capacity for flexibility, as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of highly coordinated behaviors remains unknown. Here we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg-laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg-laying and locomotion while also biasing the animals towards low-speed dwelling behavior over longer timescales. The acute effects of HSN on egg-laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal projections. The long-lasting effects on dwelling are mediated by HSN release of serotonin that is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal for the first time that neurons can borrow serotonin from one another to control behavior.

3.
Curr Biol ; 33(20): 4430-4445.e6, 2023 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-37769660

RESUMO

Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neurons in the circuits that generate behaviors have a remarkable capacity for flexibility as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of adaptive behaviors remains unknown. Here, we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg laying and locomotion while also biasing the animals toward low-speed dwelling behavior over minutes. The acute effects of HSN on egg laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal compartments. The long-lasting effects on dwelling are mediated in part by HSN release of serotonin, which is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal that neurons can borrow serotonin from one another to control behavior.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/fisiologia , Neurônios Motores/fisiologia , Serotonina/fisiologia , Oviposição/fisiologia , Neurônios Serotoninérgicos
4.
Chem Commun (Camb) ; 57(82): 10719-10722, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34581714

RESUMO

A Cu-catalyzed coupling reaction of indanone oxime acetates with thiols has been developed for the synthesis of 2,3-functionalized 1-indenones. This protocol has several features including easy mild reaction conditions, stabilized enamine products, good tolerance of functional groups, and no external oxidants. This reaction enables direct derivatization on the indanone ring to provide valuable functionalized indenones at room temperature.

5.
Org Lett ; 22(11): 4429-4434, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32383593

RESUMO

A catalytic, transition-metal-free synthesis of spiroisoxazolines is outlined. This protocol provides, for the first time, a direct access to spiroisoxazolines from aryl (thio)ethers or (thio)phenols in one synthetic step via an oximation/dearomatization cascade. In this reaction, sodium nitrite plays dual roles: as a hydroxylamine source and also a precatalyst to promote the aerobic dearomatization. This methodology features unprecedented substrate scope, high yields, promising scalability, sustainable oxidant, and mild conditions.

6.
Org Lett ; 22(3): 1169-1174, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31933370

RESUMO

An electrochemical oxydihalogenation of alkynes has been developed for the first time. Using this sustainable protocol, a variety of α,α-dihaloketones can be prepared with readily available CHCl3, CH2Cl2, ClCH2CH2Cl, and CH2Br2 as the halogen source under electrochemical conditions at room temperature.

7.
Org Lett ; 22(14): 5701-5705, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32614190

RESUMO

A sulfoxide reduction/C-S bond metathesis cascade between sulfoxides and alkyl bromides has been developed to access high-value sulfides without the use of any catalysts or bases. In this cascade, classical Kornblum oxidation is employed to reduce sulfoxides with alkyl bromides in ionic liquid. This protocol features high functional tolerance, mild conditions, promising scalability, and sustainable solvents.

8.
Org Lett ; 22(17): 6827-6831, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32814422

RESUMO

An electrochemical sulfonylation of alkynes with sodium sulfinates was achieved for the first time at room temperature. Employing this electrolysis strategy, the reaction occurs efficiently under transition-metal-free, external oxidant-free, and base-free conditions and furnishes diverse alkynyl sulfones in satisfactory yield with broad functional group tolerance.

9.
Chem Commun (Camb) ; 55(83): 12495-12498, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31576384

RESUMO

A metal-free α-C-H functionalization of cyclic 1,2-diketones with aryl sulfoxides has been developed. This regioselective arylation involves nucleophilic substitution at the activated sulfoxide with a diosphenol, followed by [3,3]-sigmatropic rearrangement. This protocol can also be applied to the synthesis of polysubstituted cyclic 1,2-diketones with predictable structures by iterative arylations.

10.
Org Lett ; 21(14): 5600-5605, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31268721

RESUMO

A metal-free method for formal ß-arylation/heteroarylation of ketones through efficient cyclopropanol ring-opening cross-couplings with aryl sulfoxides at room temperature has been developed. This protocol shows a broad substrate scope and promising scalability. In addition, the utility of the ß-arylated ketones is further demonstrated through a variety of postcoupling transformations and synthetic applications.

11.
J Agric Food Chem ; 67(2): 637-643, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30601645

RESUMO

The absorbent materials synthesized from biosources with low cost and high selectivity for oils and organic solvents have attracted increasing attention in the field of oil spillage and discharge of organic chemicals. We developed a convenient surface-grafting method to prepare efficient and recyclable biobased aerogels from epoxidized soybean oil (ESO)-modified cellulose at room temperature. The porous network-like structure of the cellulose aerogel was still fully retained after undergoing hydrophobic modification with ESO. Moreover, the modified aerogels possessed excellent hydrophobicity with a water contact angle of 132.6°. Moreover, the absorbent ability of the hydrophobic cellulose aerogels was systematically assessed. The results showed that modified aerogels could retain more than 90% absorption capacity even after 30 absorption-desorption cycles, indicating that the ESO-grafted cellulose aerogels have practical applications in the oil-water separation from industrial wastewater and oil-leakage removal.


Assuntos
Celulose/química , Géis/química , Óleos/química , Óleo de Soja/química , Purificação da Água/instrumentação , Interações Hidrofóbicas e Hidrofílicas , Poluição por Petróleo/análise , Porosidade , Poluentes Químicos da Água/química
12.
ChemSusChem ; 9(23): 3330-3337, 2016 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-27863073

RESUMO

The catalytic transfer hydrogenation of furfural to the fuel additives 2-methylfuran (2-MF) and 2-methyltetrahydrofuran (2-MTHF) was investigated over various bimetallic catalysts in the presence of the hydrogen donor 2-propanol. Of all the as-prepared catalysts, bimetallic Cu-Pd catalysts showed the highest catalytic activities towards the formation of 2-MF and 2-MTHF with a total yield of up to 83.9 % yield at 220 °C in 4 h. By modifying the Pd ratios in the Cu-Pd catalyst, 2-MF or 2-MTHF could be obtained selectively as the prevailing product. The other reaction conditions also had a great influence on the product distribution. Mechanistic studies by reaction monitoring and intermediate conversion revealed that the reaction proceeded mainly through the hydrogenation of furfural to furfuryl alcohol, which was followed by deoxygenation to 2-MF in parallel to deoxygenation/ring hydrogenation to 2-MTHF. Finally, the catalyst showed a high reactivity and stability in five catalyst recycling runs, which represents a significant step forward toward the catalytic transfer hydrogenation of furfural.


Assuntos
Furaldeído/química , Furanos/síntese química , Catálise , Cobre/química , Hidrogenação , Paládio/química , Reciclagem
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