- An efficient Pd@Pro-GO heterogeneous catalyst for the α, β-dehydrogenation of saturated aldehyde and ketones
-
An Efficient Pd@Pro-GO heterogeneous catalyst was developed that can promote the α, β-dehydrogenation of saturated aldehyde and ketones in the yield of 73% ? 92% at mild conditions without extra oxidants and additives. Pd@Pro-GO heterogeneous catalyst was synthesized via two steps: firstly, the Pro-GO was obtained by the esterification reaction between graphene oxide (GO) and N-(tert-Butoxycarbonyl)-L-proline (Boc-Pro-OH), followed by removing the protection group tert-Butoxycarbonyl (Boc), which endowed the proline-functionalized GO with both the lewis acid site (COOH) and the bronsted base site (NH), besides, the pyrrolidine of proline also can form imine with aldehydes to activate these substrates; Second, palladium was dispersed on the proline-functionalized GO (Pro-GO) to obtained heterogeneous catalyst Pd@Pro-GO. Mechanistic studies have shown that the Pd@Pro-GO-catalyzed α,β-dehydrogenation of saturated aldehyde and ketones was realized by an improved heterogeneously catalyzed Saegusa oxidation reaction. Based on the obove characteristics, the Pd@Pro-GO will be widely used in the transition metal catalytic field.
- Chang, Yi-Yuan,Hao, Yue,Pan, Gao-Fei,Wang, Yi-Chen,Wang, Zhe,Xing, Rui-Guang
-
supporting information
(2021/12/30)
-
- Synthesis of Enones and Enals via Dehydrogenation of Saturated Ketones and Aldehydes
-
A general, efficient and economic palladium-catalyzed dehydrogenation to form enones or enals has been developed. The approach possesses extremely broad substrate scope including various linear or cyclic saturated ketones and aldehydes. The protocol is ligand-free, and molecular oxygen is used as the sole clean oxidant in the reaction. Due to mild reaction conditions, good functional group compatibility, and versatile utilities of enones and enals, the method can be applied in the late-stage synthesis of natural products, pharmaceuticals and fine chemicals. (Figure presented.).
- Pan, Gao-Fei,Zhu, Xue-Qing,Guo, Rui-Li,Gao, Ya-Ru,Wang, Yong-Qiang
-
p. 4774 - 4783
(2018/11/10)
-
- The present invention relates to a new process for the preparation of heliotropine
-
The invention relates to a method for preparing helional and discloses a method which comprises steps of carrying out Claisen-Schmidt condensation reaction between heliotropin serving as a raw material and propionaldehyde under the catalysis of strong-basicity ion exchange resin, and further performing catalytic hydrogenation so as to obtain the target product. The method is characterized in that the strong-basicity ion exchange resin is used to replace other strong bases for catalyzing Claisen-Schmidt condensation reaction, the reaction yield is greatly improved, disproportionation reaction which can cause relevant impurities is avoided, and the purification is easy. The method is a route which is high in yield, low in cost, safe and applicable for industrial synthesis.
- -
-
Page/Page column 4; 5
(2017/02/17)
-
- Neutral nazarov-type cyclization catalyzed by palladium(0)
-
Joining the circle: The first Pd0 catalyzed Nazarov-type cyclization of diketoesters (see scheme) proceeds in 70 % to 95 % yield under strictly neutral pH conditions. Aryl substitution of the diketoesters is not required, so the reaction shows great versatility and can also proceed with aliphatic substrates. Copyright
- Shimada, Naoyuki,Stewart, Craig,Bow, William F.,Jolit, Anais,Wong, Kahoano,Zhou, Zhe,Tius, Marcus A.
-
supporting information; experimental part
p. 5727 - 5729
(2012/08/07)
-
- An organocatalytic asymmetric nazarov cyclization
-
An organocatalytic asymmetric Nazarov cyclization of diketoesters that proceeds by means of a dual activation mechanism has been developed. Screening of a number of catalysts led to a new thiourea that incorporates a primary amino group. The method gives rise to cyclic products with two adjacent quaternary asymmetric carbon atoms, one of which is an all-carbon stereocenter, with complete or nearly complete diastereoselectivity and in high or very high enantiomeric excess. A brief and very convenient synthesis of the acyclic diketoester starting materials through nucleophilic addition to a ketene is also described.
- Basak, Ashok K.,Shimada, Naoyuki,Bow, William F.,Vicic, David A.,Tius, Marcus A.
-
supporting information; experimental part
p. 8266 - 8267
(2010/08/04)
-
- Aromatic amides as potentiators of bioefficacy of anti-infective drugs
-
The present invention relates to an aromatic substituted pentadienoic acid amides and there use in combination of specific amounts of aromatic amides i.e. 4-alkyl-5-(substituted phenyl)-2(E),4(E)-pentadienoic acid amides, its geometrical isomers or their dihydro or tetrahydro derivatives and an anti-infective drug useful in potentiating the bioefficacy of antiinfective drug. The combination of the present invention is useful in the treatment of certain infections and disease at lower concentration of anti-infectives necessary to inhibit the growth of microbial strains and may also find applications in reducing the resistance in microorganisms.
- -
-
Page/Page column 9
(2008/06/13)
-
- AROMATIC SUBSTITUTED PENTADIENOIC ACID AMIDE FOR COMBINATION WITH ANTI-INFECTIVE DRUGS
-
The present invention relates to an aromatic substituted pentadienoic acid amides and there use in combination of specific amounts of aromatic amides i.e. 4-alkyl-5-(substituted phenyl)-2(E),4(E)-pentadienoic acid amides, its geometrical isomers or their dihydro or tetrahydro derivatives and an anti-infective drug useful in potentiating the bioefficacy of antiinfective drug. The combination of the present invention is useful in the treatment of certain infections and disease at lower concentration of anti-infectives necessary to inhibit the growth of microbial strains and may also find applications in reducing the resistance in microorganisms.
- -
-
-
- Supported choline hydroxide (ionic liquid) as heterogeneous catalyst for aldol condensation reactions
-
Choline hydroxide was used as a basic catalyst for aldol condensation reactions to produce new C-C bonds between several ketones and aldehydes. Choline supported on MgO exhibits higher TOF values than other well known basic catalysts in these reactions.
- Abello, Sonia,Medina, Francisco,Rodriguez, Xavier,Cesteros, Yolanda,Salagre, Pilar,Sueiras, Jesus E.,Tichit, Didier,Coq, Bernard
-
p. 1096 - 1097
(2007/10/03)
-
- PHOSPHONATES α-LITHIES AGENTS DE TRANSFERT FONCTIONNEL. PREPARATION D'ALDEHYDES α,β-INSATURES α-SUBSTITUES.
-
Condensation of α-lithioalkylphosphonates with ethoxymethyleneaniline leads to lithiated enaminoalkylphosphonates directly convertible on reaction with aldehydes into α,β-unsaturated α-substituted aldehydes.
- Tay, M. K.,Aboujaoude, E. E.,Collignon, N.,Savignac, Ph.
-
p. 1263 - 1266
(2007/10/02)
-