917-92-0Relevant academic research and scientific papers
Preparation method of 3, 3-dimethyl-1-butyne
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Paragraph 0028-0031; 0034-0043, (2021/04/17)
The invention discloses a preparation method of 3, 3-dimethyl-1-butyne, which comprises the following steps: by using tert-butyl alcohol and acetylene which are simple, readily available and cheap as initial raw materials and using transition metal salt which is readily available on the market as a catalyst, directly reacting in the presence of acid to obtain a product, and carrying out simple distillation separation to obtain a high-purity product. The method is simple and convenient to operate, less in environmental pollution, good in product quality, high in yield, low in cost and more suitable for industrial production.
Synthesis method of terbinafine medical intermediate tert-butyl acetylene
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Paragraph 0015; 0016, (2017/03/14)
A synthesis method of terbinafine medical intermediate tert-butyl acetylene includes the following steps of adding 310 ml of potassium bisulfite solution and 300 ml of potassium bisulfite to a reaction vessel provided with a stirrer, a thermometer, a dropping funnel and a condenser, raising the temperature of the solution to 90-95 DEG C, controlling the stirring speed at 150-170 rpm, dropwise adding 0.73 mol of 1,1-diamido-3,3-dimethylbutane, controlling the dropwise adding time at 3-5 hours, adding 0.81-0.84 mol of hypochloric acid phenyl ester, conducting reaction for 90-120 min, raising the temperature of the solution to 110-115 DEG C, continuing to conduct reaction for 3-5 hours, lowering the temperature of the solution to 10-15 DEG C, separating out solid, conducting filtering, saline solution washing, acetonitrile washing and pressure reduction distillation, collecting fraction of 100-108 DEG C, and conducting recrystallization in cyclohexane to obtain crystal tert-butyl acetylene.
Lanthanide-Catalyzed Reversible Alkynyl Exchange by Carbon–Carbon Single-Bond Cleavage Assisted by a Secondary Amino Group
Shao, Yinlin,Zhang, Fangjun,Zhang, Jie,Zhou, Xigeng
supporting information, p. 11485 - 11489 (2016/10/24)
Lanthanide-catalyzed alkynyl exchange through C?C single-bond cleavage assisted by a secondary amino group is reported. A lanthanide amido complex is proposed as a key intermediate, which undergoes unprecedented reversible β-alkynyl elimination followed by alkynyl exchange and imine reinsertion. The in situ homo- and cross-dimerization of the liberated alkyne can serve as an additional driving force to shift the metathesis equilibrium to completion. This reaction is formally complementary to conventional alkyne metathesis and allows the selective transformation of internal propargylamines into those bearing different substituents on the alkyne terminus in moderate to excellent yields under operationally simple reaction conditions.
"quick and click" assembly of functionalised indole rings via metal-promoted cyclative tandem reactions
Capitta, Francesca,De Luca, Lidia,Porcheddu, Andrea
, p. 59297 - 59301 (2015/02/19)
An efficient and convenient synthesis of a variety of decorated indoles using a three-component tandem metal-catalysed process is described. We propose here a new "synthetic kit" that allows for the "quick and click" assembly of indole rings using readily available, and inexpensive starting materials under environmentally friendly reaction conditions. This journal is
Substituent effects on the photorearrangements of unsymmetrically substituted diazinobarrelenes
Hsieh, Hsing-Pang,Chen, Ann-Cheng,Villarante, Nelson R.,Chuang, Gary J.,Liao, Chun-Chen
, p. 1165 - 1178 (2013/03/14)
A series of diazinobarrelenes 8-15 engendered with alkyl functionalities at the barrelene skeleton were irradiated with 350 nm light under direct and acetone-sensitized reaction conditions. Under these conditions, all the barrelenes except barrelene 14 afforded semibullvalenes with varying degrees of regioselectivity and product distribution. Dicyanopyrazinobarrelenes 8-10 which furnished semibullvalenes 32-41via the aryl-vinyl initial bridging route were strongly controlled by the nitrile functionalities installed at the aromatic sites. Benzoquinoxalinobarrelenes 11-13 which afforded semibullvalenes 42-49, preferentially underwent photorearrangement via vinyl-vinyl bridging even if the compounds were excited at a wavelength where the quinoxaline moiety absorbed most of the light. Zimmerman's bridging hypothesis and the possibility for quinoxalines to undergo intramolecular triplet energy transfer could reasonably account for the observed regioselectivity. Barrelene 14 was insensitive to photorearrangement whereas benzo[f,h]quinoxalinobarrelene 15 preferentially underwent ADPM rearrangement affording semibullvalenes 50-52. Electronic and steric factors of alkyl substituents overwhelmingly controlled the product forming steps whereas localization and minimization of triplet energies greatly influenced the initial bridging interaction. The Royal Society of Chemistry 2013.
Weakly nucleophilic conjugate bases of superacids as powerful nucleophiles in vinylic bimolecular nucleophilic substitutions of simple β- alkylvinyl(aryl)-λ3-bromanes
Ochiai, Masahito,Okubo, Takuji,Miyamoto, Kazunori
supporting information; experimental part, p. 3342 - 3344 (2011/05/04)
We report herein, for the first time, the stereoselective synthesis of simple (E)-β-alkylvinyl(aryl)-λ3-bromanes via a boron-λ3-bromane exchange reaction and their unique bimolecular nucleophilic substitutions at the vinylic ipso carbon atom under mild conditions. Interestingly, even weakly nucleophilic anions such as conjugate bases of superacids (HBF4, TfOH, Tf2CH 2, Tf3CH, Tf2NH, etc.) function as nucleophiles toward the vinyl-λ3-bromanes. For instance, the vinylic SN2 reaction of (E)-vinyl-λ3-bromanes with potassium bis(triflyl)methanide stereoselectively produced (Z)-vinyloxy oxosulfonium ylides with exclusive inversion of configuration via oxygen attack, while that with potassium bis(triflyl)imide afforded predominantly (Z)-vinyloxysulfoximines. In marked contrast, (E)-β-alkylvinyl- λ3-iodanes do not undergo the vinylic SN2 reaction with these conjugate bases of superacids. The differences between the nucleofugalities of aryl-λ3-iodanyl and aryl- λ3-bromanyl groups (the latter being greater) probably play a pivotal role in these unique reactions.
Thieme Chemistry Journal Awardees - Where are they now? A general one-step synthesis of alkynes from enolisable carbonyl compounds
Lyapkalo, Ilya M.,Vogel, Michael A. K.,Boltukhina, Ekaterina V.,Vav?ík, Ji?í
scheme or table, p. 558 - 561 (2009/07/09)
Terminal and internal acetylenes were obtained in good to excellent isolated yields from carbonyl compounds by converting the carbonyl functionality into the enol nonaflate intermediate followed by elimination to give the C-C triple bond. The one-pot transformations were uniformly induced by phosphazene bases combined with mildly electrophilic nonafluorobutane-1-sulfonyl fluoride. The method is the most general among those reported to date as it applies to both acyclic ketones and aldehydes. Only moderate kinetic regioselectivity in favour of alk-1-yne achieved from methyl n-alkyl ketone represents a limitation of the method. In all the other instances, individual acetylenic products were obtained. Georg Thieme Verlag Stuttgart.
Removal of water - a factor influencing the synthesis of alkynes in a phase-transfer catalyzed β-elimination reaction
Zakrzewski,Huras,Sas,Zelechowski,Bombinska
, p. 1051 - 1057 (2008/09/21)
Acetylene derivatives 4 were synthesized from the corresponding vicinal bromo compounds 2 in the phase-transfer catalyzed hydrogen bromide β-elimination reaction using solid potassium hydroxide as a base, xylene as a solvent, and a phase-transfer catalyst. The yields of the synthesized acetylene derivatives 4 were substantially improved when water formed in the process had been removed.
Reaction of C-silylated α-diazophosphines as nucleophiles toward carbonyl compounds: A mechanistic study and application to the synthesis of alkynes and α-hydroxyphosphonamides
Illa, Ona,Bagan, Xavier,Cazorla, Anna M.,Lyon, Celine,Baceiredo, Antoine,Branchadell, Vicenc,Ortuno, Rosa M.
, p. 5320 - 5327 (2007/10/03)
Diversely substituted α-hydroxyphosphonamides and alkynes have been efficiently synthesized through the reaction of C-silylated α- diazophosphines with different types of aldehydes (2 equiv) in a neutral medium under very mild conditions. The reaction with some chiral aldehydes is highly diastereoselective leading to phosphonamides as single diastereomers. The novel reaction is influenced by electronic and steric effects being precluded for aromatic aldehydes containing electron-releasing substituents on the phenyl ring and for bulky aliphatic aldehydes. The mechanistic studies of these processes, which are highly exothermic, provide evidence for a nucleophilic attack of the diazophosphine to the aldehyde leading to a betaine that rapidly rearranges to a diazomethylenephosphorane, which has been detected or captured in some instances. The diazomethylenephosphorane reacts with a second molecule of aldehyde according to a Wittig-type condensation, and the rate-determining step of the whole process is believed to be the decomposition of the resultant oxaphosphetane to afford the hydroxyphosphonamide and a diazocumulene. Finally, this intermediate loses molecular nitrogen giving a transient carbene that rapidly evolves toward the alkyne.
Regioselective synthesis of novel heterophanes from 4-amino-triazoles
Chande, Madhukar S.,Athalye, Shailesh S.,Godbole, Ajit A.
, p. 670 - 673 (2007/10/03)
The regioselective synthesis of N-amino-benztriazolophanes has been achieved by incorporation of benzene nucleus in the heterophane. The some of the novel compounds have been studied for their use as PTC agents.
