78725-73-2Relevant academic research and scientific papers
Laccase-mediated Oxidations of Propargylic Alcohols. Application in the Deracemization of 1-arylprop-2-yn-1-ols in Combination with Alcohol Dehydrogenases
González-Granda, Sergio,Méndez-Sánchez, Daniel,Lavandera, Iván,Gotor-Fernández, Vicente
, p. 520 - 527 (2019/11/16)
The catalytic system composed by the laccase from Trametes versicolor and the oxy-radical TEMPO has been successfully applied in the sustainable oxidation of fourteen propargylic alcohols. The corresponding propargylic ketones were obtained in most cases in quantitative conversions (87–>99 % yield), demonstrating the efficiency of the chemoenzymatic methodology in comparison with traditional chemical oxidants, which usually lead to problems associated with the formation of by-products. Also, the stereoselective reduction of propargylic ketones was studied using alcohol dehydrogenases such as the one from Ralstonia species overexpressed in E. coli or the commercially available evo-1.1.200, allowing the access to both alcohol enantiomers mostly with complete conversions and variable selectivities depending on the aromatic pattern substitution (97–>99 % ee). To demonstrate the compatibility of the laccase-mediated oxidation and the alcohol dehydrogenase-catalyzed bioreduction, a deracemization strategy starting from the racemic compounds was developed through a sequential one-pot two-step process, obtaining a selection of (S)- or (R)-1-arylprop-2-yn-1-ols with excellent yields (>98 %) and selectivities (>98 % ee) depending on the alcohol dehydrogenase employed.
Relay Catalysis to Synthesize β-Substituted Enones: Organocatalytic Substitution of Vinylogous Esters and Amides with Organoboronates
Sundstrom, Sasha,Nguyen, Thien S.,May, Jeremy A.
supporting information, p. 1355 - 1359 (2020/02/13)
Organocatalysis was shown to facilitate conjugate additions to vinylogous esters and amides for the first time. Subsequent elimination of a β-alcohol or amine provided π-conjugated β-substituted enones. Remarkably, nucleophile addition to the electron-rich vinylogous substrates is more rapid than classical enones, forming monosubstituted products. A doubly organocatalytic (organic diol and methyl aniline) conjugate addition synthesized the products directly from alkynyl ketones. Both of these catalytic transformations are orthogonal to transition metal catalysis, allowing for good yields, easily accessible or commercially available reagents, high selectivity, reagent recovery and recyclability, facile scalability, and exceptional functional group tolerance.
Covalent Adaptable Networks with Tunable Exchange Rates Based on Reversible Thiol–yne Cross-Linking
Du Prez, Filip E.,Guerre, Marc,Maes, Diederick,Unal, Kamil,Van Herck, Niels,Winne, Johan M.
supporting information, p. 3609 - 3617 (2020/02/04)
The design of covalent adaptable networks (CANs) relies on the ability to trigger the rearrangement of bonds within a polymer network. Simple activated alkynes are now used as versatile reversible cross-linkers for thiols. The click-like thiol–yne cross-linking reaction readily enables network synthesis from polythiols through a double Michael addition with a reversible and tunable second addition step. The resulting thioacetal cross-linking moieties are robust but dynamic linkages. A series of different activated alkynes have been synthesized and systematically probed for their ability to produce dynamic thioacetal linkages, both in kinetic studies of small molecule models, as well as in stress relaxation and creep measurements on thiol–yne-based CANs. The results are further rationalized by DFT calculations, showing that the bond exchange rates can be significantly influenced by the choice of the activated alkyne cross-linker.
A novel synthesis of N-hydroxy-3-aroylindoles and 3-aroylindoles
Ieronimo, Gabriella,Palmisano, Giovanni,Maspero, Angelo,Marzorati, Alessandro,Scapinello, Luca,Masciocchi, Norberto,Cravotto, Giancarlo,Barge, Alessandro,Simonetti, Marco,Ameta, Keshav Lalit,Nicholas, Kenneth M.,Penoni, Andrea
supporting information, p. 6853 - 6859 (2018/10/20)
A straightforward indole synthesis via annulation of C-nitrosoaromatics with conjugated terminal alkynones was realised achieving a simple, highly regioselective, atom- and step economical access to 3-aroylindoles in moderate to good yields. Further functionalizations of indole scaffolds were investigated and an easy way to JWH-018, a synthetic cannabinoid, was achieved.
Synthesis and cytotoxicity evaluation of aryl triazolic derivatives and their hydroxymethine homologues against B16 melanoma cell line
Kalhor-Monfared, Shiva,Beauvineau, Claire,Scherman, Daniel,Girard, Christian
supporting information, p. 436 - 441 (2016/07/15)
In this manuscript we describe synthesis and cytotoxicity evaluation of some triazolic derivatives against B16 melanoma cell line. For this purpose, we transformed a set of aromatic aldehydes into terminal alkynes, using Besthmann-Ohira reagent, and we made the corresponding hydroxymethyl homologated alkynes by an acetylene Grignard reagent. These generated two sets of alkynes were then subjected to a copper(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) using a solid-supported catalyst (Amberlyst A-21?CuI), with a third set composed of organic azides. Synthesized triazoles were then tested in?vitro against B16 melanoma cell line. Amongst them, compounds a1b1 (R1?=?p-nitrophenyl, R2?=?benzyl), a4b1 (R1?=?naphthyl, R2?=?benzyl) and a4b5 (R1?=?naphthyl, R2?=?(R/S)- dioxolane) showed the best activity against B16 melanoma cells, with IC50of 5.12, 3.89 and 6.60?μM respectively.
Highly stereoselective kinetic resolution of α-allenic alcohols: An enzymatic approach
Li, Wenhua,Lin, Zuming,Chen, Long,Tian, Xuechao,Wang, Yan,Huang, Sha-Hua,Hong, Ran
supporting information, p. 603 - 606 (2016/01/20)
A highly efficient lipase AK-catalyzed direct kinetic resolution of a variety of α-allenic alcohols was developed. With the complementary to previous studies, the current reaction system is effective on a broad range of substituents (R1) at C(1), such as alkyl, aryl, alkenyl, and alkynyl groups. The Jones-Burgess empirical model was modified to interpret the reversed selectivity during the acetylation of secondary alcohol. The methyl group at C(2) of allenic alcohols implied a small structural adjustment in the catalytic triad of lipase AK, representing a potential direction for future site-directed mutagenesis.
HBF4-Catalysed Nucleophilic Substitutions of Propargylic Alcohols
Barreiro, Elena,Sanz-Vidal, Alvaro,Tan, Eric,Lau, Shing-Hing,Sheppard, Tom D.,Dez-Gonzlez, Silvia
supporting information, p. 7544 - 7549 (2016/01/26)
The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C-O, C-N and C-C bonds in technical acetone and in air. Good to excellent yields and good chemoselectivities were obtained using low acid loading (typically 1 mol-%) under simple reaction conditions. The activity of HBF4 (aq. solution) as a catalyst in propargylation reactions is presented. C-O, C-N and C-C bonds were formed in technical acetone and in air. Good to excellent yields were obtained using low acid loading (typically 1 mol-%) under mild reaction conditions.
Gold(I)-catalysed tandem cyclisation of propargyl acetals and vinyl esters
Siah, Huey-San Melanie,Kaur, Maya,Iqbal, Naseem,Fiksdahl, Anne
, p. 1727 - 1740 (2014/03/21)
The results of our previous comparative study of chemoselective gold(I)-catalysed alkene cycloadditions of propargyl substrates demonstrated that propargyl acetals react by different cyclisation pathways from the corresponding esters, and that they also have significantly higher reactivities. To increase understanding of the chemistry of propargyl acetals and to explore the possibilities of generating new compounds through gold(I)-catalysed reactions, a range of reactions of propargyl acetals with vinyl esters have been carried out. A new type of cyclopropyl-cyclopentenyl products, (1,3-dimethoxy-4,5-diphenylcyclopent-2-en-1-yl)-cyclopropyl ester derivatives, was obtained. A plausible mechanism, including sequential [1+2] and [2+3] cycloadditions, is proposed for these highly regio- and stereoselective gold(I)-catalysed reactions. The cyclopentenylation took place stereoselectively, whereas cis/trans mixtures of diastereoisomers were formed in the cyclopropanation step, with the selectivity being controlled by the bulkier vinylic substituent. The tandem reaction allows the construction of polysubstituted and highly functionalised bicyclic compounds. Copyright
Gold(I)-Catalysed Tandem Cyclisation of Propargyl Acetals and Vinyl Esters
Siah, Huey-San Melanie,Kaur, Maya,Iqbal, Naseem,Fiksdahl, Anne
, p. 1727 - 1740 (2015/10/05)
The results of our previous comparative study of chemoselective gold(I)-catalysed alkene cycloadditions of propargyl substrates demonstrated that propargyl acetals react by different cyclisation pathways from the corresponding esters, and that they also have significantly higher reactivities. To increase understanding of the chemistry of propargyl acetals and to explore the possibilities of generating new compounds through gold(I)-catalysed reactions, a range of reactions of propargyl acetals with vinyl esters have been carried out. A new type of cyclopropyl-cyclopentenyl products, (1,3-dimethoxy-4,5-diphenylcyclopent-2-en-1-yl)-cyclopropyl ester derivatives, was obtained. A plausible mechanism, including sequential [1+2] and [2+3] cycloadditions, is proposed for these highly regio- and stereoselective gold(I)-catalysed reactions. The cyclopentenylation took place stereoselectively, whereas cis/trans mixtures of diastereoisomers were formed in the cyclopropanation step, with the selectivity being controlled by the bulkier vinylic substituent. The tandem reaction allows the construction of polysubstituted and highly functionalised bicyclic compounds.
Direct synthesis of pyrroles via 1,3-dipolar cycloaddition of azomethine ylides with ynones
Wang, Zheng,Shi, Ying,Luo, Xiaoyan,Han, De-Man,Deng, Wei-Ping
supporting information, p. 1742 - 1745 (2013/06/27)
A direct and facile synthesis of multi-substituted pyrroles via AgOAc-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with ynones is developed, providing the corresponding adducts in moderate to high yields (up to 89%).
