1846-67-9Relevant academic research and scientific papers
Highly efficient synthesis of α,β-acetylenic aldehydes from terminal alkynes using DMF as the formylating reagent
Journet, Michel,Cai, Dongwei,DiMichele, Lisa M.,Larsen, Robert D.
, p. 6427 - 6428 (1998)
The formylation of lithium acetylides with DMF led to α,β-acetylenic aldehydes in excellent yields (>94%). A reverse quench into a phosphate buffer (10% aqueous KH2PO4,4 equiv) proved to be the key for this high- yielding reaction.
A stereoselective synthesis of anti-gamma,delta-alkynyl- and -alkenyl-beta-hydroxy-alpha-amino esters from tin(II) enolates of glycinate.
Gridley, Jonathan J,Coogan, Michael P,Knight, David W,Malik, K M Abdul,Sharland, Christopher M,Singkhonrat, Jirada,Williams, Sian
, p. 2550 - 2551 (2003)
Condensations between the tin(II) enolate 11 of ethyl N-tosylglycinate and conjugated ynals 12 and ynones 14 are highly diastereoselective, in favour of the anti-isomers 13 and 15; similar reactions of enals and enones 17 show lower but still useful levels of anti-stereoselectivity.
Micelle-Mediated Trimerization of Ynals to Orthogonally Substituted 4H-Pyrans in Water: Downstream Rearrangement to Bioactive 2,8-dioxabicyclo[3.3.1]nona-3,6-diene Frameworks
Rashid, Showkat,Bhat, Bilal A.,Mehta, Goverdhan
supporting information, p. 6646 - 6651 (2021/10/14)
An efficient trimerization of ynals to diversely substituted 4H-pyran constructs has been executed in water, under ambient conditions employing micellar catalysis. The method is in agreement with the ideas of green and sustainable chemistry. The locus of the micellar reaction site has been probed through proton NMR studies. A general acid-mediated downstream rearrangement of the derived 4H-pyrans to interesting 2,8-dioxabicyclo[3.3.1]nona-3,6-dienes has been observed.
Annullatins series natural product as well as preparation method and application thereof
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Paragraph 0032; 0033; 0034; 0035, (2020/10/21)
The invention belongs to the field of medicinal chemistry, and relates to a cordyceps sinensis secondary metabolite Annullatins series natural product as well as a preparation method and application of the cordyceps sinensis secondary metabolite Annullatins series natural product. A total synthesis route is designed and established through experiments, commercially available raw materials are taken as a substrate, and the preparation of Annullatins series natural product is completed through mild reaction. According to the invention, an in-vitro anti-diabetic vascular complication activity test shows that the Annullatins series natural product designed by the invention plays a role in protecting vascular endothelial cells induced by high glucose, and is beneficial to prevention and treatment of diabetic vascular complication clinically. The Annullatins series natural product has a structural general formula shown in the specification.
Rhodium-Catalyzed 1,1-Hydroacylation of Thioacyl Carbenes with Alkynyl Aldehydes and Subsequent Cyclization
Zhou, Bingnan,Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3594 - 3599 (2019/05/24)
A rhodium-catalyzed 1,1-hydroacylation of thioacyl carbenes with alkynyl and alkenyl aldehydes and subsequent 6-endo-trig/dig cyclization are realized, giving structurally diverse 4H-thiopyran-4-ones and 2,3-dihydro-4H-thiopyran-4-ones in moderate to good yields. The oxidative addition of Rh(I) to aldehydes is proposed to be the turnover-limiting step. Manipulations of estrones demonstrate the applications of our formal (3 + 3) transannulations in the structural modifications of natural products.
Palladium-catalyzed oxidative borylation of conjugated enynones through carbene migratory insertion: synthesis of furyl-substituted alkenylboronates
Ping, Yifan,Chang, Taiwei,Wang, Kang,Huo, Jingfeng,Wang, Jianbo
supporting information, p. 59 - 62 (2019/01/03)
A palladium-catalyzed oxidative borylation reaction of conjugated enynones is developed. This reaction represents a new method for the synthesis of furyl-substituted alkenylboronates. The reaction works well with a series of conjugated enynones. Boryl migratory insertion of the palladium carbene intermediate is proposed as the key step in these transformations.
Copper-Catalyzed Asymmetric Silylation of Propargyl Dichlorides: Access to Enantioenriched Functionalized Allenylsilanes
Liu, Zheng-Li,Yang, Chao,Xue, Qi-Yan,Zhao, Meng,Shan, Cui-Cui,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 16538 - 16542 (2019/11/11)
A copper-catalyzed silylation of propargyl dichlorides was developed to access chloro-substituted allenylsilanes under mild reaction conditions. Moreover, enantioenriched chloro-substituted allenylsilanes can be synthesized in moderate to high yields and good enantioselectivities with this protocol.
Mechanistic Divergence in the Hydrogenative Synthesis of Furans and Butenolides: Ruthenium Carbenes Formed by gem-Hydrogenation or through Carbophilic Activation of Alkynes
Peil, Sebastian,Fürstner, Alois
supporting information, p. 18476 - 18481 (2019/11/14)
Enynes with a tethered carbonyl substituent are converted into substituted furan derivatives upon hydrogenation using [Cp*RuCl]4 as the catalyst. Paradoxically, this transformation can occur along two distinct pathways, each of which proceeds via discrete pianostool ruthenium carbenes. In the first case, hydrogenation and carbene formation are synchronized (“gem-hydrogenation”), whereas the second pathway comprises carbene formation by carbophilic activation of the triple bond, followed by hydrogenative catalyst recycling. Representative carbene intermediates of either route were characterized by X-ray crystallography; the structural data prove that the attack of the carbonyl group on the electrophilic carbene center follows a Bürgi–Dunitz trajectory.
Chemoselective Hydroalumination of 1-Aza-but-1-en-3-ynes (C-Iminoalkynes): Formation of Propargylamines by Imine Reduction and of 5-Aluminazoles and 1-Aza-butadienes by Anti-Michael Attack
Dahlkamp, J. Matthias,Tolzmann, Michael,Lucchesi, Ralph,Daniliuc, Constantin-Gabriel,Wibbeling, Birgit,Uhl, Werner,Würthwein, Ernst-Ulrich
, p. 1346 - 1357 (2018/05/23)
Hydroalumination of 1-aza-but-1-en-ynes 1 provides facile access to propargylamines 4 by reduction of the C=N bonds or alternatively to 1-aza-buta-1,3-dienes 6 by reduction of the triple bond. The chemoselectivity depends not only on the steric properties of both the hydroalumination agent (di-iso-butylaluminum (DIBAL-H, iBu2AlH) versus di-tert-butylaluminum hydride (tBu2AlH)) and the substrates but also on the reaction temperatures. In several cases, initial aluminum species of 5-aluminazole type 5 could be isolated and characterized by X-ray diffraction, indicating an "anti-Michael" addition of the hydride to the triple bond. Aqueous workup of those species led to 1-azabutadiene derivatives 6. High-level DFT calculations indicate that the observed chemoselectivity is only compatible with a dimeric nature of the hydroaluminating agent. Using such a dimer, the imine reduction corresponds to the kinetically controlled pathway, whereas the triple bond reduction leads to the thermodynamically much more stable 5-aluminazoles, 5.
Gold-Catalyzed [4 + 1]-Annulation Reactions between 1,4-Diyn-3-ols and Isoxazoles to Construct a Pyrrole Core
Kardile, Rahul Dadabhau,Kale, Balaji S.,Sharma, Pankaj,Liu, Rai-Shung
supporting information, p. 3806 - 3809 (2018/07/25)
This work reports gold-catalyzed [4 + 1]-annulation reactions between 1,4-diyn-3-ols and isoxazoles or benzisoxazoles to yield pyrrole derivatives. The reaction chemoselectivity is controlled by an initial attack of an isoxazole at a less hindered alkyne to form gold carbenes, further inducing a 1,2-migration of a second alkyne group. A broad substrate scope of 1,4-diyn-3-ols, isoxazoles and even benzisoxazoles highlighted the reaction utility.
