104597-03-7Relevant academic research and scientific papers
Mild and expedient asymmetric reductions of α,β-unsaturated alkenyl and alkynyl ketones by TarB-NO2 and mechanistic investigations of ketone reduction
Eagon, Scott,Delieto, Cassandra,McDonald, William J.,Haddenham, Dustin,Saavedra, Jaime,Kim, Jinsoo,Singaram, Bakthan
, p. 7717 - 7725 (2010)
A facile and mild reduction procedure is reported for the preparation of chiral allylic and propargyl alcohols in high enantiomeric purity. Under optimized conditions, alkynyl and alkenyl ketones were reduced by TarB-NO 2 and NaBH4 at 25 °C in 1 h to produce chiral propargyl and allylic alcohols with enantiomeric excesses and yields up to 99%. In the case of α,β-unsaturated alkenyl ketones, α-substituted cycloalkenones were reduced with up to 99% ee, while more substituted and acyclic derivatives exhibited lower induction. For α,β-ynones, it was found that highly branched aliphatic ynones were reduced with optimal induction up to 90% ee, while reduction of aromatic and linear aliphatic derivatives resulted in more modest enantioselectivity. Using the (l)-TarB-NO2 reagent derived from (l)-tartaric acid, we routinely obtained highly enantioenriched chiral allylic and propargyl alcohols with (R) configuration. Since previous models and a reduction of a saturated analogue predicted propargyl products of (S) configuration, a series of new mechanistic studies were conducted to determine the likely orientation of aromatic, alkenyl, and alkynyl ketones in the transition state.
Zinc-salen-catalyzed asymmetric alkynylation of alkyl acylsilanes
Li, Feng-Quan,Zhong, Shi,Lu, Gui,Chan, Albert S. C.
, p. 1955 - 1960 (2009)
Optically active tertiary propargylic alcohols are useful and versatile building blocks in organic synthesis, and their direct access by enantioselective addition of alkyne nucleophiles to ketones has achieved significant progress over the last ten years. In view of the potential applications of acylsilanes as useful synthetic equivalents of aldehydes, we described a general catalytic enantioselective addition of terminal alkynes to alkyl acylsilanes. After reaction optimization involving variation of solvent, tern-perature, catalyst ratio and various catalysts screen, the in situ generated Zn-salen complex was chosen as catalyst. With hexane as solvent, the silylated tertiary propargylic alcohols were obtained in satisfactory yields and ees for both aliphatic and aromatic alkynes.
Efficient Synthesis of Polysubstituted Furans through a Base-Promoted Oxacyclization of (Z)-2-En-4-yn-1-ols
Hrizi, Asma,Thiery, Emilie,Romdhani-Younes, Moufida,Jacquemin, Johan,Thibonnet, Jér?me
, p. 3798 - 3806 (2021)
An efficient base catalyzed oxacyclization of Z-enynols has been developed under transition metal-free reaction conditions, thus resulting in a variety of new di-, tri-, and tetra-substituted furans. This approach allowed us to obtain 32 new compounds. Furthermore, DFT calculations were realized to depict a relationship between the natural population analysis and experimental results with alkyl or aryl groups for the synthesis of 2-benzylfuran. A one-pot Sonogashira/oxacyclization approach offers a flexible, robust and efficient alternative to base catalyzed cyclization is also carried out.
Torquoselectivity in the nazarov reactions of allenyl vinyl ketones
Morgan, Timothy D. R.,Leblanc, Luc M.,Ardagh, Giselle H.,Boyd, Russell J.,Burnell, D. Jean
, p. 1042 - 1051 (2015)
Nazarov reactions mediated by BF3-etherate of a series of carbon-substituted allenyl vinyl ketones provided intermediates in which substituents on the termini of the allenes had rotated away from the vinyl moieties, and these intermediates were
Photoinduced Gold-Catalyzed Domino C(sp) Arylation/Oxyarylation of TMS-Terminated Alkynols with Arenediazonium Salts
Alcaide, Benito,Almendros, Pedro,Busto, Eduardo,Lázaro-Milla, Carlos
, p. 2177 - 2186 (2017)
A selective and convenient synthesis of tri- and tetrasubstituted α,β-unsaturated ketones, as well as 2,3-diarylbenzofurans has been developed with the aid of light and taking advantage of a cooperative gold/photoredox-catalyzed 2-fold arylation reaction of TMS-terminated alkynols. The reaction of 3-(trimethylsilyl)prop-2-yn-1-ols was competent to generate diarylated α,β-unsaturated ketones; whereas the photoredox sequence involving 2-[(trimethylsilyl)ethynyl]phenol exclusively afforded 2,3-diarylbenzofurans. The reaction of terminal alkynes proceeded in poor yields while the use of bulkier silyl groups, such as TIPS, resulted unproductive. Apparently, the C(sp) arylation reaction is the first event on the domino bis-arylative sequence. These results could be explained through the intermediation of arylgold(III) species and several single electron transfer processes.
Reactions of phenylethynyl cuprates of lanthanides with organyl halides and synthesis of the related polyfunctional compounds
Zhil'tsov,Druzhkova,Dydykina,Makarov
, (2014)
Phenylethynyl cuprate complexes of lanthanides react with organyl halides RX, Ph3CX, R3SiX, and RC(O)X (X = Cl, I; R = alkyl) in tetrahydrofuran to give polyfunctional organic and hetero-organic compounds with high yield. The reactio
Polypyrrole-supported graphite felt for acetylene coupling reaction in solid phase
Kashiwagi, Yoshitomo,Chiba, Shinya,Ikezoe, Hiroshi,Anzai, Jun-Ichi
, p. 2513 - 2516 (2004)
Substrate immobilization on graphite felt for solid-phase acetylene coupling reaction was achieved by electrochemical polymerization of the substrate precursor containing a pyrrole side chain, where the amount of substrate on the electrode surface was easily controlled by the number of repeated cyclic voltammetric scannings. Couplings between terminal acetylenes and the iodobenzene-modified graphite felt electrode or aromatic iodides and the terminal acetylene-modified graphite felt electrode in the presence of palladium catalyst proceeded smoothly in satisfactory yields.
Kinetic Resolution of Propargylic Ethers via [2,3]-Wittig Rearrangement to Synthesize Chiral α-Hydroxyallenes
Xu, Xi,Dong, Shunxi,Feng, Lili,Wang, Sijing,Liu, Xiaohua,Feng, Xiaoming
, p. 2692 - 2696 (2020)
An efficient kinetic resolution of propargyloxy dicarbonyl compounds via asymmetric [2,3]-Wittig rearrangement was achieved by using a chiral N,N′-dioxide/NiII complex catalyst. Various chiral α-allenyl alcohols were obtained in high enantioselectivities under mild conditions. The utility of this method was readily demonstrated in the asymmetric synthesis of the chiral 2,5-dihydrofuran derivative.
Enantiopure (S)-4-phenyl-3-butyn-2-ol and (S)-1-phenyl-2-butanol through an enzymatic reduction
Musa, Musa M.
, p. 8363 - 8365 (2014)
This paper describes an enzymatic approach to producing (S)-4-phenyl-3-butyn-2-ol [(S)-3] and (S)-1-phenyl-2-butanol [(S)-4] from their corresponding ketones. W110A secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus (W110A TeSADH), a Prelog mutant of TeSADH, is used as a biocatalyst in this approach. The enantioselective reduction of α,β-alkynyl ketone 4-phenyl-3-butyn-2- one produced (S)-3 in an excellent yield and high levels of both chemo- and enantio-selectivities keeping the alkynyl moiety intact. The reduction of 1-phenyl-2-butanone (2) produced (S)-4 of higher enantioselectivity than that observed previously in the W110A TeSADHcatalyzed reduction of phenylacetone, a ketone with one methylene unit less than compound 2.
Palladium-catalyzed cyclocotrimerization of propargyl alcohols with aryl halides
Oi, Shuichi,Orihara, Hideki,Kawai, Hiroshi,Inoue, Yoshio
, p. 621 - 625 (2005)
Tertiary propargyl alcohols react with aryl halides in the presence of K2CO3 and a catalytic amount of palladium(0) complex affording 2:1 cyclocotrimerization products, 3-benzylidene-2,3-dihydrofuranes (3).
