227078-24-2Relevant articles and documents
Chemoselective reduction of aldehydes: Via a combination of NaBH4 and acetylacetone
Sui, Guoqing,Lv, Qingyun,Song, Xiaoqing,Guo, Huihui,Dai, Jiatong,Ren, Li,Lee, Chi-Sing,Zhou, Wenming,Hao, Hong-Dong
supporting information, p. 15793 - 15796 (2019/10/19)
A bench-stable combination of NaBH4-acetylacetone was developed for the efficient chemoselective reduction of aldehydes in the presence of ketones. This method offers a useful synthetic protocol for distinguishing carbonyl reaction sites, and its synthetic utility is reflected by its moisture tolerance and high efficiency in a variety of complex settings.
Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: Chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles
Zhang, Song-Lin,Deng, Zhu-Qin
, p. 7282 - 7294 (2016/08/05)
A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.
Selective transformations of carbonyl functions in the presence of α,β-unsaturated ketones: Concise asymmetric total synthesis of decytospolides A and B
Yahata, Kenzo,Minami, Masaki,Watanabe, Kei,Fujioka, Hiromichi
supporting information, p. 3680 - 3683 (2014/08/05)
Enones selectively react with a combination of PPh3 and TMSOTf to produce phosphonium silyl enol ethers, which work as protective groups of enones during the reduction of other carbonyl functions and can be easily deprotected to regenerate parent enones at workup. Furthermore, the first ketone selective alkylations in the presence of enones were also accomplished. This in situ protection method was applied to concise asymmetric total syntheses of decytospolides A and B.
Preparation of monometallic (Pd, Ag) and bimetallic (Pd/Ag, Pd/Ni, Pd/Cu) nanoparticles via reversed micelles and their use in the Heck reaction
Heshmatpour, Felora,Abazari, Reza,Balalaie, Saeed
experimental part, p. 3001 - 3011 (2012/05/31)
The metal nanoparticles (NPs) have been prepared using a water-in-oil microemulsion system of water/dioctyl sulfosuccinate sodium salt (aerosol-OT, AOT)/isooctane at 25 °C. Since the NPs produced in this system can endure forcing conditions (100 °C), this system has been used for the synthesis of nano-catalysts in the Heck reactions. FE-SEM, DLS, and UV/vis analyses have been used to characterize the surface morphology, size, and proof of the formation of all the prepared metal NPs, respectively. In addition, the effects of some reaction parameters (here, bases and solvents) were optimized. Differences in the catalytic properties of the synthesized NPs have also been investigated. Consequently, the Pd/Cu (4:1) bimetallic NP showed the highest activity in the C-C coupling reaction of the iodobenzene with the styrene, thus it is employed as the superior catalyst in this study. Therefore, the Pd/Cu (4:1) bimetallic NPs were further investigated using TEM and XRD analyses. This catalyst system is also reusable for six runs with very negligible reduction in the efficiency.
New scavenger resin for the reversible linking and monoprotection of functionalized aromatic aldehydes
Zhu, Mingzhao,Ruijter, Eelco,Wessjohann, Ludger A.
, p. 3921 - 3924 (2007/10/03)
(Chemical Equation Presented) Polymer-supported benzylhydrazines were synthesized using poly(ethylene glycol) acrylamide (PEGA) resin. They can be used to scavenge electrophiles reactive with hydrazine. Especially aromatic aldehydes can be captured select
