Decarbonylation of aldehydes is a basic organic transformation, which has been developed for more than six-decade. However, as comparing to well-studied aromatic aldehydes, fewer examples for catalytic decarbonylation...Decarbonylation of aldehydes is a basic organic transformation, which has been developed for more than six-decade. However, as comparing to well-studied aromatic aldehydes, fewer examples for catalytic decarbonylation of aliphatic aldehydes were reported, mainly on simple or special substrates.For α-bulky or highly functionalized ones, stoichiometric Rh(I) were usually required for decent yields.Herein, we present a rare example of Ir(I)-catalyzed direct decarbonylation of α-quaternary aldehydes with broad substrate scope and good functional group compatibility via judicious selection of ligand. Theα-chirality is memorized in this decarbonylation process. In addition, we report a broad-spectrum decarbonylation of α-secondary and α-tertiary aldehydes containing multifunctional groups with an improved Rh(I)/DPPP recipe. Finally, we realized selective decarbonylation of α-tertiary aldehydes in the presence of α-quaternary one via the reactivity differences.展开更多
目的建立流动注射法检测植物油中醛类化合物的方法。方法利用醛类物质和间苯三酚在酸催化作用下生成红色单甲川类衍生物的原理,在自制的流动注射分析仪中,以相同摩尔量的甲醛、乙醛、正丙醛、正丁醛、正戊醛、正己醛、正庚醛、正辛醛和...目的建立流动注射法检测植物油中醛类化合物的方法。方法利用醛类物质和间苯三酚在酸催化作用下生成红色单甲川类衍生物的原理,在自制的流动注射分析仪中,以相同摩尔量的甲醛、乙醛、正丙醛、正丁醛、正戊醛、正己醛、正庚醛、正辛醛和正壬醛配成的混合醛为标准物质,通过优化反应中的酸催化剂种类及用量、温度、试剂浓度以及流速等参数,确定最佳的流动注射法检测植物油中的醛类物质方法。结果最佳的流动注射条件为:两个蠕动泵的流速控制在0.5 m L/min,检测波长为455 nm,进样量为100μL,恒温水浴槽的温度为75℃。在该条件下,醛类化合物在0.0006~0.03 mol/L浓度范围内具有良好的线性关系,线性方程为Y=3.19×10~8X+1.12×10~5,r^2=0.998;该方法的相对标准偏差为0.41%~2.1%,回收率在90%以上。结论该方法可用于实际食用油样品中醛类物质的检测,具有方法简单、测试快速、数据准确的特点,可在食品检测领域中获得推广。展开更多
A novel synthetic method for the preparation of aliphatic aldehydes from the corresponding carboxylic acids via 1,3-dimethylbenzimidazolium salts is provided. 1,3-Dimethylbenzimidazolium salts were rapidly reduced wit...A novel synthetic method for the preparation of aliphatic aldehydes from the corresponding carboxylic acids via 1,3-dimethylbenzimidazolium salts is provided. 1,3-Dimethylbenzimidazolium salts were rapidly reduced with sodium/ethanol and then hydrolyzed with hydrochloric acid to obtain aliphatic aldehydes, in which the 1,3-dimethylbenzimidazolium salts can be readily achieved from the corresponding carboxylic acids. The mechanism for the reductive reaction of 1,3-dimethylbenzimidazolium salts with sodium/ethanol was discussed.展开更多
从分析醛、酮的分子结构入手,导出了醛、酮的沸点与其分子结构的关lgT=0.1324lg(W+2p+2n-2a-1.5ω)+2.3729式中 T 为一元脂肪族醛、酮的沸点(K);W 为 Wiener 径向指数;p=P-P′,P,P′分别为醛、酮及其同碳原子数的直链醛、酮的极性指数;n...从分析醛、酮的分子结构入手,导出了醛、酮的沸点与其分子结构的关lgT=0.1324lg(W+2p+2n-2a-1.5ω)+2.3729式中 T 为一元脂肪族醛、酮的沸点(K);W 为 Wiener 径向指数;p=P-P′,P,P′分别为醛、酮及其同碳原子数的直链醛、酮的极性指数;n 等于羰碳原子上的烷基数减1;a 等于 a 碳原子上的烷基数减1;ω为ω碳原子上的取代基数.展开更多
Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from al...Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from aldehydes via C(sp^(2))-H fluorination is reported.This method enables the conversion of both aliphatic and aromatic aldehydes into acyl fluorides in good to excellent yields by visible-light under mild conditions in the absence of transition-metal and external photosensitizer.A variety of functional groups were well tolerated for this transformation.This green method provides a practical pathway to synthesize acyl fluorides under mild conditions.展开更多
Ethyl N-cyanomethytbenzenecarboximidate reacted with aliphatic aldehydes under the solid-liquid PTC condition to gire a-ethoxyphenylmethylene- aminoacrylonitrile derivatives and oxazoline derivatives.It is a convenien...Ethyl N-cyanomethytbenzenecarboximidate reacted with aliphatic aldehydes under the solid-liquid PTC condition to gire a-ethoxyphenylmethylene- aminoacrylonitrile derivatives and oxazoline derivatives.It is a convenient and new method for synthesis of β,β'-dihyroxy-a-amino acids by hydrolysis of the oxazoline derivatives.展开更多
Based on the molecular polarizability effect index,a formula of three parameters was proposed to calculate the boiling point of aliphatic aldehydes and alkanones.ln（820.5-Tb）=6.38330-1.37357×10-1Nc+5.39350ΔE...Based on the molecular polarizability effect index,a formula of three parameters was proposed to calculate the boiling point of aliphatic aldehydes and alkanones.ln（820.5-Tb）=6.38330-1.37357×10-1Nc+5.39350ΔEPI+8.02603×10-2NWhere the Nc is the effective length of carbon chain of alkyl group in the aliphatic aldehydes and alkanones.The ΔPEI is the polarizability effect index difference between the corresponding branched and normal alkyl isomer containing the same carbon atom number,which expressed the effcet of carbonyl group on the boiling point of ali-phatic aldehydes and alkanones.N is the carbon numbers of aliphatic aldehydes and alkanones.展开更多
基金financial support from the National Natural Science Foundation of China (No. 21971260)Guangdong Natural Science Funds for Distinguished Young Scholar (No. 2018B030306018)+3 种基金the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (No. 2017ZT07C069)the Pearl River Talent Recruitment Program (No. 2019QN01L111)the Fundamental Research Funds for the Central Universities, Sun Yatsen University (No. 22lglj06)Innovation projects of Zhengzhou tobacco research institute (No. 442020CR0320 to Wu Fan)。
文摘Decarbonylation of aldehydes is a basic organic transformation, which has been developed for more than six-decade. However, as comparing to well-studied aromatic aldehydes, fewer examples for catalytic decarbonylation of aliphatic aldehydes were reported, mainly on simple or special substrates.For α-bulky or highly functionalized ones, stoichiometric Rh(I) were usually required for decent yields.Herein, we present a rare example of Ir(I)-catalyzed direct decarbonylation of α-quaternary aldehydes with broad substrate scope and good functional group compatibility via judicious selection of ligand. Theα-chirality is memorized in this decarbonylation process. In addition, we report a broad-spectrum decarbonylation of α-secondary and α-tertiary aldehydes containing multifunctional groups with an improved Rh(I)/DPPP recipe. Finally, we realized selective decarbonylation of α-tertiary aldehydes in the presence of α-quaternary one via the reactivity differences.
文摘目的建立流动注射法检测植物油中醛类化合物的方法。方法利用醛类物质和间苯三酚在酸催化作用下生成红色单甲川类衍生物的原理,在自制的流动注射分析仪中,以相同摩尔量的甲醛、乙醛、正丙醛、正丁醛、正戊醛、正己醛、正庚醛、正辛醛和正壬醛配成的混合醛为标准物质,通过优化反应中的酸催化剂种类及用量、温度、试剂浓度以及流速等参数,确定最佳的流动注射法检测植物油中的醛类物质方法。结果最佳的流动注射条件为:两个蠕动泵的流速控制在0.5 m L/min,检测波长为455 nm,进样量为100μL,恒温水浴槽的温度为75℃。在该条件下,醛类化合物在0.0006~0.03 mol/L浓度范围内具有良好的线性关系,线性方程为Y=3.19×10~8X+1.12×10~5,r^2=0.998;该方法的相对标准偏差为0.41%~2.1%,回收率在90%以上。结论该方法可用于实际食用油样品中醛类物质的检测,具有方法简单、测试快速、数据准确的特点,可在食品检测领域中获得推广。
基金Project supported by the National Natural Science Foundation of China （No. 21072158）, the China Postdoctoral Science Foundation （No. 20070421139）, the Special Foundation of the Education Committee of Shaanxi Province （No. 09JK750）.
文摘A novel synthetic method for the preparation of aliphatic aldehydes from the corresponding carboxylic acids via 1,3-dimethylbenzimidazolium salts is provided. 1,3-Dimethylbenzimidazolium salts were rapidly reduced with sodium/ethanol and then hydrolyzed with hydrochloric acid to obtain aliphatic aldehydes, in which the 1,3-dimethylbenzimidazolium salts can be readily achieved from the corresponding carboxylic acids. The mechanism for the reductive reaction of 1,3-dimethylbenzimidazolium salts with sodium/ethanol was discussed.
文摘从分析醛、酮的分子结构入手,导出了醛、酮的沸点与其分子结构的关lgT=0.1324lg(W+2p+2n-2a-1.5ω)+2.3729式中 T 为一元脂肪族醛、酮的沸点(K);W 为 Wiener 径向指数;p=P-P′,P,P′分别为醛、酮及其同碳原子数的直链醛、酮的极性指数;n 等于羰碳原子上的烷基数减1;a 等于 a 碳原子上的烷基数减1;ω为ω碳原子上的取代基数.
基金We thank the NSFC(No.21971093)the International Joint Research Centre for Green Catalysis and Synthesis(No.2016B01017)the 111 projects for support of our research.We also thank the Canada Research Chair(Tier I)foundation,the E.B.Eddy Endowment Fund,the Canada Foundation for Innovation,and the Natural Sciences and Engineering Research Council of Canada to Chao-Jun Li.
文摘Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from aldehydes via C(sp^(2))-H fluorination is reported.This method enables the conversion of both aliphatic and aromatic aldehydes into acyl fluorides in good to excellent yields by visible-light under mild conditions in the absence of transition-metal and external photosensitizer.A variety of functional groups were well tolerated for this transformation.This green method provides a practical pathway to synthesize acyl fluorides under mild conditions.
基金The project supported by the National Natural Science Foundation of China.Present Address:Shanghai Institute of Organic Chemistry,Academia Sinica.
文摘Ethyl N-cyanomethytbenzenecarboximidate reacted with aliphatic aldehydes under the solid-liquid PTC condition to gire a-ethoxyphenylmethylene- aminoacrylonitrile derivatives and oxazoline derivatives.It is a convenient and new method for synthesis of β,β'-dihyroxy-a-amino acids by hydrolysis of the oxazoline derivatives.
文摘Based on the molecular polarizability effect index,a formula of three parameters was proposed to calculate the boiling point of aliphatic aldehydes and alkanones.ln（820.5-Tb）=6.38330-1.37357×10-1Nc+5.39350ΔEPI+8.02603×10-2NWhere the Nc is the effective length of carbon chain of alkyl group in the aliphatic aldehydes and alkanones.The ΔPEI is the polarizability effect index difference between the corresponding branched and normal alkyl isomer containing the same carbon atom number,which expressed the effcet of carbonyl group on the boiling point of ali-phatic aldehydes and alkanones.N is the carbon numbers of aliphatic aldehydes and alkanones.
