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1.
Org Lett ; 24(38): 6993-6998, 2022 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-36122178

RESUMEN

Herein, we describe a method for synthesizing (E)-ß-iodo-α,ß-unsaturated aldehydes via the iodoformylation of terminal alkynes with TMSCF3 and NaI. This synthetic method uses inexpensive and easy-to-handle chemical feedstocks and employs a commercially available CuI catalyst. It can transform a broad range of terminal alkynes into bis-electrophile (E)-ß-iodo-α,ß-unsaturated aldehydes with excellent chemoselectivity, regioselectivity, and stereoselectivity. Moreover, it was demonstrated that this protocol has abundant organic reactivity.

2.
J Org Chem ; 87(15): 9635-9644, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35830500

RESUMEN

Herein, we developed an efficient and transition-metal-free multicomponent coupling reaction for the synthesis of aroyloxyl alkyl iodides. In the reaction among 2,4,6-triarylboroxines, THF, TMSCF3, LiOH, and NaI, five-component reactions could be precisely controlled by modulating CF3SO2Na, supplying one type of aroyloxyl alkyl iodides in moderate to high yields. The reaction exhibits good functional group tolerance and a wide substrate scope and can be easily transformed into other useful compounds. The mechanism is proposed on the basis of the control experiments.


Asunto(s)
Yoduros , Hidrocarburos Fluorados , Yoduros/química , Silanos
3.
J Org Chem ; 87(12): 7720-7733, 2022 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-35620903

RESUMEN

R2PCF2H ligands and their R2P(O)CF2H precursors were synthesized from R2P(O)H with TMSCF3 by simply modulating the H2O concentration via deoxydifluoromethylation and difluoromethylation. The air sensitive R2PCF2H phosphines can be stabilized in Cu(I) clusters as ligands. Within these Cu(I) clusters, the Sonogashira cross-coupling reaction can proceed fast and efficiently using terminal alkynes and aryl iodides within 15 min at room temperature under air to give a variety of diaryl(alkyl)acetylenes in good yields (49 examples, yields of ≤99%). Six of the internal alkynes present in drug precursors can be obtained using this protocol in good yields. The mechanism is proposed on the basis of control experiments.


Asunto(s)
Yoduros , Fosfinas , Alquinos , Catálisis , Hidrocarburos Fluorados , Ligandos , Paladio , Silanos
4.
Org Lett ; 24(15): 2826-2831, 2022 04 22.
Artículo en Inglés | MEDLINE | ID: mdl-35394275

RESUMEN

Herein, by dual C-O bond cleavage of cyclic ethers with Cu catalysis, we eventually led to the development of a selective three-component coupling of commercially available chemicals, carboxylic acids, ethers, and halogens to synthesize more than 70 iodoalkyl esters in the presence of TMSCF3. This allows for the concise synthesis of highly functionalized iodoalkyl esters directly. And the synthetic insect pheromones were also disclosed.


Asunto(s)
Ácidos Carboxílicos , Ésteres , Ácidos Carboxílicos/química , Catálisis , Ésteres/química , Éteres/química , Éteres Cíclicos , Hidrocarburos Fluorados , Silanos
5.
RSC Adv ; 8(55): 31267-31274, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-35548205

RESUMEN

The aim of this work was to study the feasibility of using fish manure waste as a nutrient source for lactic acid fermentation. Fish waste contains nitrogen and minerals that could support the growth of lactic acid bacteria (LAB), making it a good candidate as the nutrient source for lactic acid fermentation. Two different fish manure wastes, from Nile tilapia and channel catfish aquaculture, were investigated for their performance on different sugar substrates. Both fish waste types showed low efficiency in the direct fermentation of glucose, but satisfactory efficiencies in simultaneous saccharification and fermentation (SSF) of cellulosic materials, such as pure cellulose and paper sludge. The highest lactic acid yield obtained was 87% and 91%, with a corresponding volumetric productivity of 1.006 and 0.580 g L-1 h-1, and corresponding lactic acid concentration of 96 and 56 g L-1 for cellulose and paper sludge, respectively. Fish waste concentrations did not show much impact on lactic acid production for the SSF process, where increasing fish waste from 10 to 30 g L-1 resulted in less than a 10% yield increase. In the present study, fish manure waste was shown to be an effective and economic nutrient source for lactic acid production by SSF.

6.
Bioresour Technol ; 200: 713-21, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26562687

RESUMEN

Paper mill sludge (PS), a solid waste from pulp and paper industry, was investigated as a feedstock for acetone-butanol-ethanol (ABE) production by simultaneous saccharification and fermentation (SSF). ABE fermentation of paper sludge by Clostridium acetobutylicum required partial removal of ash in PS to enhance its enzymatic digestibility. Enzymatic hydrolysis was found to be a rate-limiting step in the SSF. A total of 16.4-18.0g/L of ABE solvents were produced in the SSF of de-ashed PS with solid loading of 6.3-7.4% and enzyme loading of 10-15FPU/g-glucan, and the final solvent yield reached 0.27g/g sugars. No pretreatment and pH control were needed in ABE fermentation of paper sludge, which makes it an attractive feedstock for butanol production. The results suggested utilization of paper sludge should not only consider the benefits of buffering effect of CaCO3 in fermentation, but also take into account its inhibitory effect on enzymatic hydrolysis.


Asunto(s)
Acetona/metabolismo , Butanoles/metabolismo , Metabolismo de los Hidratos de Carbono , Etanol/metabolismo , Fermentación , Papel , Aguas del Alcantarillado/química , Álcalis/farmacología , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Celulosa/metabolismo , Clostridium acetobutylicum/efectos de los fármacos , Clostridium acetobutylicum/metabolismo , Fermentación/efectos de los fármacos , Glucosa/metabolismo , Hidrólisis , Panicum/efectos de los fármacos , Xilosa/metabolismo
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