22927-31-7Relevant academic research and scientific papers
Micellar Catalysis for Sustainable Hydroformylation
Calamante, Massimo,Dei, Filippo,Maramai, Samuele,Migliorini, Francesca,Petricci, Elena
, p. 2794 - 2806 (2021/05/03)
It is here reported a fully sustainable and generally applicable protocol for the regioselective hydroformylation of terminal alkenes, using cheap commercially available catalysts and ligands, in mild reaction conditions (70 °C, 9 bar, 40 min). The process can take advantages from both micellar catalysis and microwave irradiation to obtain the linear aldehydes as the major or sole regioisomers in good to high yields. The substrate scope is largely explored as well as the application of hydroformylation in tandem with intramolecular hemiacetalization thus demonstrating the compatibility with a broad variety of functional groups. The reaction is efficient even in large scale and the catalyst and micellar water phase can be reused at least 5 times without any impact in reaction yields. The efficiency and sustainability of this protocol is strictly related to the in situ transformation of the aldehyde into the corresponding Bertagnini's salt that precipitates in the reaction mixture avoiding organic solvent mediated purification steps to obtain the final aldehydes as pure compounds.
Copper-catalyzed enantioselective synthesis of bridged bicyclic ketals from 1,1-disubstituted-4-methylene-1,6-hexanediols and related alkenols
Burde, Ameya S.,Karyakarte, Shuklendu D.,Sylvester, Eric D.,Chemler, Sherry R.
, p. 105 - 108 (2021/01/14)
Bridged bicyclic ketals display a range of bioactivities. Their catalytic enantioselective synthesis from acyclic 1,1-disubstituted alkene diols is disclosed. This reaction combines asymmetric catalysis with a distal radical migration. Alkynes and arenes
Design, synthesis, and in vitro evaluation of 4-aminoalkyl-1(2H)-phthalazinones as potential multifunctional anti-Alzheimer's disease agents
Ye, Chanyuan,Xu, Rui,Cao, Zhongcheng,Song, Qing,Yu, Guangjun,Shi, Yichun,Liu, Zhuoling,Liu, Xiuxiu,Deng, Yong
, (2021/04/22)
A series of 4-aminoalkyl-1(2H)-phthalazinone derivatives was designed and synthesized as potential multifunctional agents for Alzheimer's disease (AD) treatment. In vitro biological assay results demonstrated that most synthesized compounds exhibited sign
The studies on chemoselective promiscuous activity of hydrolases on acylals transformations
Koszelewski, Dominik,Ostaszewski, Ryszard
, (2019/02/27)
Chemoselective, mild and convenient protocol for the hydrolysis of the synthetically relevant acylals via promiscuous enzyme-catalyzed hydrolysis has been developed. It has been shown that promiscuous activity of the used hydrolases dominates their native activity related with carboxylic esters hydrolysis. The main advantage of the present methodology is that it can be conducted under neutral conditions at room temperature. Moreover, complete deprotection of acylals takes place within 10–20 min. Developed protocol can be used with compounds having a variety of hydrolytic labile groups since the cleavage is proceeded under neutral conditions and occurs exclusively on acylal moiety. Further this protocol was extended by the tandem Passerini multicomponent reaction leading to the α-acetoxy amides using acylals as the surrogates of the carbonyl components to P-MCR.
Axial-to-Central Chirality Transfer for Construction of Quaternary Stereocenters via Dearomatization of BINOLs
Min, Xiao-Long,Xu, Xu-Ran,He, Ying
, p. 9188 - 9193 (2019/11/14)
All-carbon quaternary stereocenters are versatile building blocks, and their asymmetric construction has attracted much attention. Herein, we disclose an axial-to-central chirality transfer strategy for the synthesis of chiral quaternary stereocenters via dearomatization of (S)-BINOLs. The reaction proceeded smoothly with a wide range of propargyl carbonates to afford chiral spiro-compounds in high yields with excellent enantioselectivities. In addition, the strategy was extended to kinetic resolution of rac-BINOLs albeit with moderate s value.
Tuning Regioselectivity of Wacker Oxidation in One Catalytic System: Small Change Makes Big Step
Hu, Kang-Fei,Ning, Xiao-Shan,Qu, Jian-Ping,Kang, Yan-Biao
, p. 11327 - 11332 (2018/09/06)
A regioselectivity switchable aerobic Wacker-Tsuji oxidation has been developed using catalytic tert-butyl nitrite as a simple organic redox cocatalyst. By solely switching the solvent, either substituted aldehydes or ketones could be prepared under mild
Catalytic Oxygenative Allylic Transposition of Alkenes into Enones with an Azaadamantane-Type Oxoammonium Salt Catalyst
Nagasawa, Shota,Sasano, Yusuke,Iwabuchi, Yoshiharu
, p. 10276 - 10279 (2017/08/07)
The first catalytic oxygenative allylic transposition of unactivated alkenes into enones has been developed using an oxoammonium salt as the catalyst. This reaction converts various tri- and trans-disubstituted alkenes into their corresponding enones with transposition of their double bonds at ambient temperature in good yields. The use of a less-hindered azaadamantane-type oxoammonium salt as the catalyst and a combination of two distinct stoichiometric oxidants, namely, iodobenzene diacetate and magnesium monoperoxyphthalate hexahydrate (MMPP?6 H2O) are essential to facilitate the enone formation efficiently.
Effect of Partially Fluorinated N-Alkyl-Substituted Piperidine-2-carboxamides on Pharmacologically Relevant Properties
Vorberg, Raffael,Trapp, Nils,Zimmerli, Daniel,Wagner, Bj?rn,Fischer, Holger,Kratochwil, Nicole A.,Kansy, Manfred,Carreira, Erick M.,Müller, Klaus
, p. 2216 - 2239 (2016/10/19)
The modulation of pharmacologically relevant properties of N-alkyl-piperidine-2-carboxamides was studied by selective introduction of 1–3 fluorine atoms into the n-propyl and n-butyl side chains of the local anesthetics ropivacaine and levobupivacaine. The basicity modulation by nearby fluorine substituents is essentially additive and exhibits an exponential attenuation as a function of topological distance between fluorine and the basic center. The intrinsic lipophilicity of the neutral piperidine derivatives displays the characteristic response noted for partially fluorinated alkyl groups attached to neutral heteroaryl systems. However, basicity decrease by nearby fluorine substituents affects lipophilicities at neutral pH, so that all partially fluorinated derivatives are of similar or higher lipophilicity than their non-fluorinated parents. Aqueous solubilities were found to correlate inversely with lipophilicity with a significant contribution from crystal packing energies, as indicated by variations in melting point temperatures. All fluorinated derivatives were found to be somewhat more readily oxidized in human liver microsomes, the rates of degradation correlating with increasing lipophilicity. Because the piperidine-2-carboxamide core is chiral, pairs with enantiomeric N-alkyl groups are diastereomeric. While little response to such stereoisomerism was observed for basicity or lipophilicity, more pronounced variations were observed for melting point temperatures and oxidative degradation.
Formal enantioselective synthesis of aplykurodinone-1
Peixoto, Philippe A.,Jean, Alexandre,Maddaluno, Jacques,De Paolis, Michael
, p. 6971 - 6973 (2013/07/26)
Step economy and simplicity were combined in the asymmetric formal synthesis of aplykurodinone-1 (see scheme; TBS=tert-butyldimethylsilyl). The key features of the strategy involve a one-pot aerobic and directed oxidation/deoxygenation and a late-stage co
Self-assembled bidentate ligands for ru-catalyzed anti-Markovnikov hydration of terminal alkynes
Chevallier, Floris,Breit, Bernhard
, p. 1599 - 1602 (2008/02/02)
(Figure Presented) In pairs: Bidentate ligands are generated by the self-assembly of monodentate ligands through complementary hydrogen bonding. A ruthenium complex bearing such self-assembled heterodimeric ligands is used as the catalyst in the regioselective hydration of terminal alkynes. FG = functional group, Piv = pivaloyl.
