F:Flammable;
693-02-7Relevant articles and documents
Relative Migratory Aptitudes of Alkyl Groups in the Iodination of Lithium Ethynyltrialkylborates
Slayden, Suzanne W.
, p. 2311 - 2314 (1981)
Relative migratory aptitudes of various alkyl groups have been determined in the iodine-induced rearrangement of lithium ethynyltrialkylborates.Trialkylboranes of types R3-nBR'n and thexyl-BRR' were complexed with lithium acetylide-ethylenediamine.Iodination, followed by deiodoboration of the rearranged intermediates, produced 1-alkynes in amounts which depend, after statistical correction, on the relative rates of alkyl group migration in an intramolecular competition.In some cases, the migratory aptitude was found to depend on the alkyl substitution pattern in the organoborate.The overall migratory aptitude order is bicyclooctyl > n-butyl > cyclohexyl, isobutyl, sec-butyl > thexyl.When the secondary and primary migrating carbon series are considered separately, the order is consistently bicyclooctyl > cyclohexyl > sec-butyl, and n-butyl > isobutyl.
Potassium Dimesitylphosphinite Catalyzed Intermolecular Hydrophosphorylation of Alkynes
H?rling, Stephan M.,Fener, Benjamin E.,Krieck, Sven,G?rls, Helmar,Westerhausen, Matthias
, p. 4380 - 4386 (2018)
In this investigation we evaluated the scope of the intermolecular hydrophosphorylation (Pudovik reaction) of alkynes R1-C-C-R2 (R1 = H, alkyl, Ph; R2 = alkyl, Ph, COOMe, SiMe3, Si(iPr)3) with bis(2,4,6-trimethylphenyl)phosphane oxide (dimesitylphosphane oxide, Mes2P(O)H) in tetrahydrofuran at room temperature or 65 °C, catalyzed with 5 or 10 mol % of potassium dimesitylphosphinite (Mes2P-O-K), yielding alkenyldimesitylphosphane oxides (Mes2P(O)-C(R1)=C(H)R2). This procedure requires substituents with a -I effect at the C-C triple bond, whereas alkyl-substituted alkynes are inactive under these reaction conditions. The hydrophosphorylation proceeds regioselectively, but E/Z isomer mixtures are obtained. E/Z isomerization occurs at elevated temperatures with an estimated energy barrier of 59 kJ mol-1 (R1 = Me; R2 = Ph). Trimethylsilyl substituents at the alkyne functionality (R1 = H, nBu; R2 = SiMe3) destabilize the product, leading to degradation and formation of Mes2P-O-SiMe3 and R1-C-C-H.
Method for synthesizing terminal alkyne by utilizing 1, 2-dihaloalkane
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Paragraph 0022-0024, (2020/04/29)
The invention discloses a method for synthesizing terminal alkyne by utilizing 1, 2-dihaloalkane. According to the method, 1, 3-dihaloalkane is used as a raw material and terminal alkyne is synthesized under the action of alkali and a catalyst, wherein the molar ratio of the alkali to the 1, 2-dihaloalkane is 2: 1-5: 1, the use amount of the catalyst is 2%-10% of the mass of the 1, 2-dihaloalkane,the reaction temperature is 100-150 DEG C and the reaction time is 3-10 h. The method has the advantages of environmental protection, high selectivity, high yield and the like.
Palladium-Catalyzed Cascade Intramolecular Cyclization and Allylation of Enynoates with Allylic Alcohols
Qiu, Sheng-Qi,Ahmad, Tanveer,Xu, Yun-He,Loh, Teck-Peng
, p. 6729 - 6736 (2019/06/14)
A Pd(II)-catalyzed mild and highly regioselective 6-endo cyclization/allylation reaction of enynoates with simple allylic alcohols has been developed. Under mild reaction conditions, the vinyl palladium species generated in situ after cyclization could insert C-C double bond of allylic alcohol through cross-coupling reaction and lead to the formation of allyl pyrone via β-OH elimination. This cascade cross-coupling reaction represents a direct and atom economic methodology for the construction of novel allyl pyrones in moderate to good yields.
Na2S-mediated synthesis of terminal alkynes from: Gem -dibromoalkenes
Singh, Radhey M.,Nandini, Durgesh,Bharadwaj, Kishor Chandra,Gupta, Tanu,Singh, Raj Pal
, p. 9979 - 9982 (2017/12/26)
The Na2S-mediated facile synthesis of terminal alkynes from gem-dibromoalkenes, at 20/40 °C under open flask conditions has been developed. Various precursors derived from heteroaromatic/aromatic/aliphatic aldehydes were found compatible. The reaction is proposed to proceed through the Fritsch-Buttenberg-Wiechell (FBW) rearrangement involving the corresponding vinyl carbene. Using mild reaction conditions with inexpensive Na2S·9H2O under air atmosphere has significant advantages over earlier routes.
AGRICULTURAL PHEROMONE COMPOSITIONS COMPRISING POSITIONAL ISOMERS
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Paragraph 0368, (2017/06/12)
The present disclosure provides pheromone compositions. In some aspects, the compositions taught herein comprise a pheromone chemically corresponding to the pheromone naturally produced by a given insect, along with at least one positional isomer of said pheromone. In various aspects, pheromone compositions of the present disclosure are able to modulate the response of the insect based on the ratio of natural pheromone to its positional isomer.
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.
SYNTHESIS OF OLEFINIC ALCOHOLS VIA ENZYMATIC TERMINAL HYDROXYLATION
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Paragraph 0286; 0287, (2016/01/30)
In certain aspects, the present invention provides methods for producing terminally hydroxylated alkenes and alkynes by contacting an unsaturated or saturated hydrocarbon substrate with a hydroxylase enzyme. Exemplary terminal hydroxylases useful for carrying out the methods of the invention exhibit strong selectivity towards one terminal carbon of a hydrocarbon substrate and include, but are not limited to, non-heme diiron alkane monooxygenases, cytochromes P450 (e.g., cytochromes P450 of the CYP52 and CYP153 family), as well as long chain alkane hydroxylases. In some embodiments, the terminally hydroxylated alkene or alkyne is further converted to a terminal alkenal. In certain embodiments, terminally hydroxylated alkenes and alkynes are useful as insect pheromones which modify insect behavior. In other embodiments, terminally hydroxylated alkenes and alkynes are useful intermediates for producing pheromones via acetylation or oxidation of the alcohol moiety.
Catalytic and computational studies of N-heterocyclic carbene or phosphine-containing copper(I) complexes for the synthesis of 5-iodo-1,2,3-triazoles
Lal, Steven,Rzepa, Henry S.,Diez-Gonzalez, Silvia
, p. 2274 - 2287 (2014/07/21)
Two complementary catalytic systems are reported for the 1,3-dipolar cycloaddition of azides and iodoalkynes. These are based on two commercially available/readily available copper complexes, [CuCl(IPr)] or [CuI(PPh 3)3], which are active at low metal loadings (PPh 3 system) or in the absence of any other additive (IPr system). These systems were used for the first reported mechanistic studies on this particular reaction. An experimental/computational-DFT approach allowed to establish that (1) some iodoalkynes might be prone to dehalogenation under copper catalysis conditions and, more importantly, (2) two distinct mechanistic pathways are likely to be competitive with these catalysts, either through a copper(III) metallacycle or via direct-activation of the starting iodoalkyne.
Reactions of perfluorinated alkenyl-, alkynyl-, alkyltrifluoroborates, and selected hydrocarbon analogues with the halogenating agents Hal2 (Hal = F, Cl, Br), "brF" (BrF3-Br2 1:1), and ICl
Bardin, Vadim V.,Adonin, Nicolay Yu.,Frohn, Hermann-Josef
, p. 565 - 579 (2012/05/20)
Reactions of [Bu4N][RBF3] [R = CnF 2n+1CF=CF (cis, trans), CF2=CF, CF2=C(CF 3), trans-C4H9CF=CF, trans-C6H 5CF=CF, C4H9CH=CH (cis, trans), CF 3C≡C, and C4H9C≡C] with chlorine, bromine, BrF3 + Br2 (as equivalent of "BrF"), and ICl in solution (CH2Cl2, CHCl3, CF 3CH2CF2CH3) led to 1, 2-addition of halogen and/or replacement of boron by halogen (halodeboration). The reaction of [Bu4N][CF3C≡CBF3] with less than equimolar amounts of diluted fluorine (5 %) in 1, 1, 1, 3, 3-pentafluorobutane (PFB) showed only [Bu4N][CF3CF2CF 2BF3] as fluorine addition product besides extensive fluorodeboration. Suspensions of the insoluble K[CF2=CFBF 3] salt reacted with Cl2 and Br2 in CH 2Cl2 giving preferentially products of halogen addition across the C=C bond. In reactions with ICl iododeboration with formation of CF2=CFI occurred besides 1, 2-addition with formation of [CF 2I-CFClBF3]-. The halodeboration reaction of[Bu4N][trans-C4H9CF=CFBF3] with Br2, "BrF", and ICl, of K[trans-C6H 5CF=CFBF3] with Br2, and of [Bu 4N][trans-C4F9CF=CFBF3] with ICl proceeded stereospecifically. Copyright
