5664-17-5Relevant academic research and scientific papers
THE IR, RAMAN AND NMR SPECTRA AND CONFORMATIONS OF CYCLOHEXYLALLENE
Gatial, A.,Horn, A.,Klaeboe, P.,Nielsen, C. J.,Pedersen, B.,et al.
, p. 59 - 66 (1990)
Three conformers of cyclohexylallene, designated I, II and III, were observed in the IR and Raman spectra.Metastable crystals formed by annealing an amorphous solid from 80 K to 140 K, and crystals formed under a pressure of 30 kbar at ambient temperature, contained conformer II.The stable crystals obtained after heating the metastable crystals to 195 K contained conformer I.The conformer III was observed as a minor component in a nitrogen matrix heated to 900 K before deposition.Negligible intensity variations between the bands of conformer I and II were observedwith nozzle temperatures 300-900 K in the argon and nitrogen matrices, indicating a ΔH0(I-II) below 0.4 kJ mol-1 while ΔH0(III-II) was equal to 6.5 kJ mol-1 and a barrier higher than ca. 11 kJ mol-1 was observed between the latter.Variable temperature measurements in Raman indicate ΔH0(I-II) ca. 0.9 kJ mol-1 in the liquid.The 13C NMR spectra show that in deuteromethanol solution the equatorial conformer dominates ( = 2percent a at 193 K, ΔG0(a-e) ca. 6.4 kJ mol-1).Analysing the temperature dependence of the vicinal H-H coupling across the cyclohexane - allene carbon bond on the basis of a gauche anti equilibrium it is found 40percent anti and 60percent gauche in methanol solution at ambient temperature.We conclude that the abundant conformers II and I being respectively the anti and the gauche conformer, while III is the anti axial conformer.
Design and synthesis of polymerizable cumulated double bond system. - Living coordination polymerization of alkylallenes by Π-allylnickel catalyst-
Endo, Takeshi,Takagi, Koji,Tomita, Ikuyoshi
, p. 15187 - 15196 (1997)
The coordination polymerization of monoalkylallenes (2a; 1,2-nonadiene, 2b; 1,2-heptadiene. 2c; cyclohexylallene. 2d; t-butylallene) was carded out by [Π-allyl)NiOCOCF3]2 (1). The polymerization was found to proceed through a living process without any side reactions to yield soluble polymers in high yields, where the resulting polymers had predictable molecular weights and narrow molecular weight distributions. The coordination polymerization of dialkylallene (2e; 3-methyl- 1,2-nonadiene, 2f; 2,3- nonadiene) was also carried out to obtain soluble polymers, although the polymerization rate of 2f was found to be considerably low compared with those of monoalkylallenes.
Preparation of (E)-1,3-Enyne Derivatives through Palladium Catalyzed Hydroalkynylation of Allenes
Liu, Zhi-Kai,Yang, Ying,Zhan, Zhuang-Ping
supporting information, p. 1589 - 1597 (2022/01/20)
A general and efficient palladium catalyzed hydroalkynylation of allenes was developed to produce synthetically versatile (E)-1,3-enyne derivatives with high regio- and stereoselectivity. This catalytic system proceeded under mild conditions and was compatible with a broad range of substrates, especially for allenes without electron-bias groups. This work further broadens the synthetic potential of these scaffolds in organic synthesis and medicinal chemistry.
Palladium-Catalyzed Carbonylative Four-Component Synthesis of β-Perfluoroalkyl Amides
Geng, Hui-Qing,Wu, Xiao-Feng,Zhang, Youcan
supporting information, p. 17682 - 17687 (2021/10/25)
Transition-metal-catalyzed multicomponent carbonylation is one of the most efficient strategies to construct carbonyl-containing compounds. Herein, a palladium-catalyzed four-component perfluoroalkylation/aminocarbonylation of unactivated alkenes with per
Copper(ii)-catalyzed protoboration of allenes in aqueous media and open air
Nekvinda, Jan,Santos, Webster L.,Snead, Russell F.
supporting information, p. 14925 - 14931 (2021/09/04)
A method has been developed for the facile Cu(ii)-catalyzed protoboration of monosubstituted allenes in aqueous media under atmospheric conditions. The reaction occurs site selectively, favoring internal alkene protoboration to afford 1,1-disubstituted vinylboronic acid derivatives (up to 93?:?7) with modest to good yields. The method has been applied to a variety of phenylallene derivatives as well as alkyl-substituted allenes. This journal is
Trifluoromethylation of Allenes: An Expedient Access to α-Trifluoromethylated Enones at Room Temperature
Brochetta, Massimo,Borsari, Tania,Gandini, Andrea,Porey, Sandip,Deb, Arghya,Casali, Emanuele,Chakraborty, Arka,Zanoni, Giuseppe,Maiti, Debabrata
supporting information, p. 750 - 753 (2019/01/04)
A silver(I) catalyzed regioselective trifluoromethylation of allenes using Langlois's salt (NaOSOCF3) is demonstrated. This transformation enables direct expedient access to α-trifluoromethylated acroleins, which are valuable synthons for a number of pharmaceuticals and agrochemicals containing vinyl-CF3 moieties. Versatility of this trifluoromethylation method has been established with good yield and excellent regioselectivity. Preliminary experiments and computational studies were carried out to elucidate the mechanistic insight of this protocol.
Enantioselective Copper-Catalyzed Three-Component Carboboronation of Allenes: Access to Functionalized Dibenzo [b,f][1,4]oxazepine Derivatives
Deng, Hao,Meng, Ziwei,Wang, Sifan,Zhang, Zheming,Zhang, Yaqi,Shangguan, Yu,Yang, Fazhou,Yuan, Dekai,Guo, Hongchao,Zhang, Cheng
supporting information, p. 3582 - 3587 (2019/07/17)
A copper-catalyzed enantioselective three-component difunctionalization of allenes with seven-membered cyclic imines and bis(pinacolato)diboron (B2(Pin)2) to approach functionalized dibenzo[b,f][1,4]oxazepine derivatives is developed. The chiral products are obtained in up to 81% yield, >20:1 dr, and 98% ee when either a chiral diphosphine ligand or a chiral ferrocenyl-based P,N-ligand is used. Furthermore, the reaction exhibits reversed diastereoselectivities when the chiral diphosphine ligand and the chiral P,N-ligand are used respectively. (Figure presented.).
A 1, 1 - disubstituted [...] compound synthesis method
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Paragraph 0055-0057, (2019/03/28)
The invention discloses a 1, 1 - disubstituted [...] compound synthesis method, the catalyst cuprous chloride, carbene precursor, the tertiary butyl alcohol potassium is added in the Schlenk reaction tube, vacuum, in an inert gas conditions, adding tetrahydrofuran, stir; then the [...][...], type I shown and methanol is dissolved in the tetrahydrofuran zincon after, in the Schlenk reaction tube of the instillment to states, for 25 °C stirring for 1 - 5 hours, the resulting reaction solution after treatment of formula II shown in 1, 1 - disubstituted [...] compound. Synthesis method of the invention has catalyst is cheap and easy to obtain and the low toxicity, high selectivity, environment friendly, mild reaction conditions, functional group universal good and simple operation and the like.
Copper-Catalyzed Propargylic Reduction with Diisobutylaluminum Hydride
Kim, Yuna,Lee, Hanseul,Park, Sunga,Lee, Yunmi
supporting information, p. 5478 - 5481 (2018/09/13)
A mild and efficient method for the synthesis of allenes through selective copper-catalyzed hydride addition to propargylic chlorides using commercially available diisobutylaluminum hydride has been developed. This transformation, which is promoted by a readily accessible N-heterocyclic carbene-copper complex, provides a wide range of new and versatile functionalized allenes in good to excellent yields with high regio- A nd stereoselectivities.
Nickel-catalyzed substitution reactions of propargyl halides with organotitanium reagents
Li, Qing-Han,Liao, Jung-Wei,Huang, Yi-Ling,Chiang, Ruei-Tang,Gau, Han-Mou
, p. 7634 - 7642 (2014/12/11)
A simple and mild catalytic coupling reaction of propargyl halides with organotitanium reagents is reported. The reaction of propargyl bromide with organo-titanium reagents mediated by NiCl2(2 mol%) and PCy3(4 mol%) in CH2
