- Metal-Free, DBU-Mediated, Microwave-Assisted Synthesis of Benzo[c]xanthones by Tandem Reactions of Alkynyl-1,3-diketones
-
A base-mediated, green, microwave-assisted efficient preparation of a diverse benzoxanthone library from variety of readily accessible γ-alkynyl 1,3-diketones is reported. The synthesis is based on tandem reactions involving intramolecular cyclization, propargyl-allenyl isomerization, and electrocyclization in one pot. Some of the benzoxanthones are also synthesized by the one-pot reaction of 1,3-diketone and alkynyl bromide under basic heating conditions. This transformation also results in the construction of one new C?C bond and one new C?O bond. (Figure presented.).
- Liang, Yi-En,D. Barve, Balaji,Kuo, Yao-Haur,Fang, Hsu-Wei,Kuo, Ting-Shen,Li, Wen-Tai
-
supporting information
p. 505 - 511
(2020/12/01)
-
- Synthesis of Highly Substituted Biaryls by the Construction of a Benzene Ring via in Situ Formed Acetals
-
Herein, we present an interesting method for the construction of a benzene ring using propargylic alcohols and 1,3-dicarbonyls, which involves three new C-C bond formations via cascade alkylation, formylation, annulation, and aromatization to make substituted biaryls. This one-pot Br?nsted acid-promoted protocol utilizes the unique reactivity of the acetal formed under the reaction conditions. Alkynyl methyl ketones could be employed instead of 1,3-dicarbonyls as they are converted to 1,3-dicarbonyls by hydration under the reaction conditions.
- Balamurugan, Rengarajan,Manojveer, Seetharaman,Tarigopula, Chandrahas
-
p. 11871 - 11883
(2021/09/13)
-
- Non-metal catalytic method for preparing 1,3-diketone compounds based on acetyenic ketone
-
The invention discloses a non-metal catalytic method for preparing 1,3-diketone compounds based on acetyenic ketone. The preparation method is a stepwise method or a one-pot method. The stepwise method comprises the following steps: mixing an acetyenic ketone compound I, a nitrogen-containing aromatic compound II and a No.1 base for a reaction, performing separation and purification to obtain an intermediate product, mixing the intermediate product and a No.2 base for a reaction, and performing separation and purification to obtain the product; and the one-pot method comprises the following steps: firstly mixing an acetyenic ketone compound I and a nitrogen-containing aromatic compound II, adding a No.1 base, performing a reaction for a period of time, adding a No.2 base, continuing a reaction for a period of time, and finally performing separation and purification to obtain the product. The method provided by the invention has mild reaction conditions, simple operation and a higher yield, wherein the yield is generally 80% or more, and the method has greater practical application value in drug synthesis.
- -
-
Paragraph 0056-0059
(2020/02/19)
-
- An effective preparation of both 1,3-diketones and nitriles from alkynones with oximes as hydroxide sources
-
An effective phosphine-catalyzed protocol has been established for the syntheses of 1,3-diketones and nitriles from alkynones with oximes as hydroxide surrogates. This method features the use of a phosphine catalyst, compatibility with various functional groups and ambient temperature, which makes this approach very practical. A plausible mechanism was proposed.
- Chen, Pei,Zhang, Qian-Qian,Guo, Jia,Chen, Lu-Lu,Wang, Yan-Bo,Zhang, Xiao
-
p. 6958 - 6966
(2018/10/02)
-
- Polycyclic compound including nitrogen and organic light emitting device using same
-
The present invention relates to a polycyclic compound including nitrogen and an organic light emitting device using the same.
- -
-
Paragraph 0146; 0147; 0148
(2016/10/10)
-
- PYRAZOLE-BASED COMPOUND AND ORGANIC LIGHT EMITTING DEVICE USING THE SAME
-
The present invention relates to a pyrazole-based compound and an organic light-emitting device using the same. The compound is represented by chemical formula 1. The compound described in the present invention can be used as an organic matter layer mater
- -
-
Paragraph 0118-0121
(2016/10/08)
-
- Transition-metal-free formal decarboxylative coupling of ?±-oxocarboxylates with ?±-bromoketones under neutral conditions: A simple access to 1,3-diketones
-
A transition-metal-free formal decarboxylative coupling reaction between ?±-oxocarboxylates and ?±-bromoketones to synthesize 1,3-diketone derivatives is presented. In this reaction, a broad scope of substrates can be employed, and neither a metal-based reagent nor an additional base is required. DFT calculations reveal that this reaction proceeds through a coupling followed by decarboxylation mechanism and the ?±-bromoketone unprecedentedly serves as a nucleophile under neutral conditions. The rate-determining step is an unusual hydrogen-bond-assisted enolate formation by thermolysis.
- He, Zhen,Qi, Xiaotian,Li, Shiqing,Zhao, Yinsong,Gao, Ge,Lan, Yu,Wu, Yiwei,Lan, Jingbo,You, Jingsong
-
p. 855 - 859
(2015/02/05)
-
- Asymmetric transfer hydrogenation of unsymmetrical benzils
-
In this paper, the asymmetric transfer hydrogenation of unsymmetrical benzils with m, p-substituents was conducted with a substrate/catalyst molar ratio of 100 at 40°C for 24 h to produce (S,S)-hydrobenzoins in good yields (76.2% to 97.1%) with high diastereomeric (syn/anti = 10.8 to 29.7/1) and enantiomeric purities (86.1%ee syn to 98.9%ee syn). Unfortunately, the unsymmetrical benzils with the o-substituents such as electron-donating (R = CH3, OCH3) and electron-withdrawing groups (R = F, Cl, CF3) resulted in poor yields (0% to 31.2%), even at 40°C for 72 h. These products had inefficient diastereoselectivities (syn/anti = 1.5 to 5.0/1) caused by steric effects. Furthermore, the results of a dynamic-kinetic study were used to propose a plausible reaction pathway of unsymmetrical benzil using 3-methoxy-1,2-diphenyl ethanedione as an example.
- Zhang, Hao,Feng, Dandan,Sheng, Haibo,Ma, Xuebing,Wan, Jinwei,Tang, Qian
-
p. 6417 - 6423
(2014/02/14)
-
- Transition-metal-free intramolecular Ullmann-type O-arylation: Synthesis of chromone derivatives
-
(Chemical Equation Presented) Expect the upexpected: A transition-metal- free approach to access chromone derivatives has been developed. The intramolecular O-arylation of substituted 1-(2-haloaryl)-propane-1,3-diones in DMF in the presence of K2CO3 gave the corresponding target products in good to excellent yields (see scheme; DMF = N,N′- dimethylformamide).
- Zhao, Jie,Zhao, Yufen,Fu, Hua
-
supporting information; experimental part
p. 3769 - 3773
(2011/05/15)
-
- The EPR D-parameter of 1,3-diarylcyclopentane-1,3-diyl triplet diradicals as a probe for steric substituent effects in benzyl-type radicals
-
The zero-field splitting D parameter of a set of ortho-substituted-1,3-diarylcyclopentane-1,3-diyl triplet diradicals 3 has been determined by EPR spectroscopy in a 2-methyltetrahydrofuran glass matrix at 77 K. While for meta- and para-substituted triplet
- Adam, Waldemar,Van Barneveld, Claus,Gerke, Jan-Stefan,Klaerner, Frank Gerrit
-
p. 2723 - 2728
(2007/10/03)
-
- Tetrafluorophenethylaralkylamine compounds
-
New fluoro derivatives of aralkylamine compounds, particularly 2-(2-phenyl-1,1,2,2-tetrafluoroethyl)benzylamine, as well as the N-alkyl and the N,N-dialkyl derivatives thereof are prepared by reaction of 2-bromobenzonitrile with benzylmagnesium chloride to produce 2'-bromo-2-phenylacetophenone; oxidation of said acetophenone with selenous acid to produce 2-bromobenzil; conversion of the benzil compound by treatment with sulfur tetrafluoride to the corresponding 2-bromo-α ,α-α',α'-tetrafluorobibenzyl; followed by reaction of the 2-bromobibenzyl compound with a metal cyanide to produce the corresponding 2-(2-phenyl-1,1,2,2-tetrafluoroethyl)benzonitrile. This nitrile compound is then reduced with lithium aluminum hydride to produce the corresponding benzylamine, which is then converted, if desired, to the N-alkyl and/or N,N-dialkyl 2-(2-phenyl-1,1,2,2-tetrafluoroethyl)benzylamine. Alternatively, the nitrile or the precursor bromobibenzyl can be converted by Grignard reactions to the corresponding α-alkyl or α,α-dialkylbenzylamine which can then be converted if desired to the corresponding N-alkyl and/or N,N-dialkyl substituted benzylamine compound. The phenyltetrafluoroethylbenzylamine as well as its N-alkyl and N,N-dialkyl derivatives are active as antiarrhythmic agents.
- -
-
-