A process of preparing olefins of the formula (I) is described herein:
with R
1
being a substituted or unsubstituted (C
1
-C
30
)hydrocarbyl, and R
2
being a substituted or unsubstituted (C
1
-C
20
)hydrocarbyl. The process includes reacting a compound of formula (II)
wherein Ar is chosen from
in the presence of a palladium-based catalyst and an organic solvent.
A process of preparing olefins of the formula (III) is also described:
with R
3
being a substituted or unsubstituted (C
1
-C
30
)hydrocarbyl, R
4
being a substituted or unsubstituted (C
1
-C
20
)hydrocarbyl, and R
5
being a substituted or unsubstituted (C
1
-C
30
) hydrocarbyl. The process includes reacting a compound of formula (IV)
wherein Ar is chosen from
with a compound of formula (V)
wherein Ar is chosen from
in the presence of a palladium-based catalyst and an organic solvent.
Visible‐Light Catalyzed [1+2+2] Cycloaddition Reactions Enabled by the Formation of Methylene Nitrones
作者:Jing Guo、Ying Xie、Wen‐Tian Zeng、Qiao‐Lei Wu、Jiang Weng、Gui Lu
DOI:10.1002/adsc.202000858
日期:2020.12.8
Nitrones are key intermediates in organic synthesis. Herein, we report the first photo‐redox synthesis of methylene nitrone intermediates from nitroarenes and arylamines. The highly reactive methylene nitrones are in situ trapped by alkenes to afford various isoxazolidines. This three‐component reaction features the use of N,N‐dimethylanilines or N‐aryl glycines as C1 building blocks, which allow for
6-Halo-2-pyridone as an efficient organocatalyst for ester aminolysis
作者:Takeshi Yamada、Yusuke Watanabe、Sentaro Okamoto
DOI:10.1039/d1ra04651a
日期:——
catalysed esteraminolysis in which not only reactive aryl esters but also relatively less reactive methyl and benzyl esters could be used as a substrate. The reaction could be performed without strictly dry and anaerobic conditions and the 6-chloro-2-pyridone catalyst could be recovered quantitatively after reaction. The method could be applied to dipeptide synthesis from methyl or benzyl esters of amino
An investigation of activities and paraoxon sensitivities of hepatic aliesterases in β-naphthoflavone-treated rats
作者:Angela M. Watson、Howard Chambers、Janice E. Chambers
DOI:10.1016/0378-4274(94)90108-2
日期:1994.5
Aliesterases (carboxylesterases, EC 3.1.1.1) are serine esterases which may protect acetylcholinesterase during organophosphorus insecticide intoxication by providing alternative phosphorylation sites. Levels of hepatic aliesterase activity were investigated after the intraperitoneal administration of beta-naphthoflavone (BNF) to female rats using nine 4-nitrophenyl esters as substrates (including straight and branched chain aliphatic and aromatic esters) and I-naphthyl acetate. In addition, the in vitro sensitivities of aliesterases to inhibition by paraoxon, the active metabolite of the common insecticide parathion, were studied. Hepatic aliesterases from BNF-treated rats displayed lower activities than those from the controls with all substrates except 4-nitrophenyl phenylbutyrate and isovalerate. The aliesterases from BNF-treated rats were more sensitive to paraoxon inhibition with 4-nitrophenyl phenylbutyrate, valerate, and butyrate. Esterases hydrolyzing 4-nitrophenyl butyrate, valerate, and branched chain esters were most sensitive to paraoxon inhibition while those hydrolyzing 4-nitrophenyl hexanoate and aromatic esters were least sensitive. The results suggested that BNF-induced changes in hepatic aliesterases could alter responses to organophosphates.
Selective Decarbonylation of Fatty Acid Esters to Linear α-Olefins
作者:Alex John、Büsra Dereli、Manuel A. Ortuño、Hillis E. Johnson、Marc A. Hillmyer、Christopher J. Cramer、William B. Tolman
DOI:10.1021/acs.organomet.7b00411
日期:2017.8.14
mixed-ligand system exploiting the trans-spanning diphosphine XantPhos and an N-heterocyclic carbene (IPr) was identified as the most effective in yielding high α-selectivity and high conversions of the ester (>98% selectivity, >90% conversion using 2.5 mol % of PdCl2 and 5 mol % of the ligands, 190 °C, 2–2.5 h). On the basis of insights from modeling at the density functional level of theory, we propose