841-07-6

Usage

Physical state

Colorless liquid

Solubility

Insoluble in water, soluble in organic solvents (ethanol and ether)

Uses

a. Solvent in various industrial processes
b. Chemical intermediate in the production of other organic compounds
c. Manufacturing of plasticizers
d. Manufacturing of rubber chemicals
e. Other industrial products

Toxicity

Relatively non-toxic

Health and environmental hazards

Low health and environmental hazards associated with its use

Upstream product

• 104-51-8 1-butylbenzene 
• 116785-83-2 1,3,5-tributyroylbenzene 
• 693-02-7 hex-1-yne 
• 74-86-2 acetylene 
• 75-05-8 acetonitrile 
• 201230-82-2 carbon monoxide 
• 292638-85-8 acrylic acid methyl ester 
• 536-74-3 phenylacetylene 
• 109-65-9 1-bromo-butane 
• 108-70-3 1,3,5-trichlorobenzene 
• 626-39-1 1,3,5-trisbromobenzene 
• 15676-66-1 tri-n-butylindium 
• 591-78-6 n-hexan-2-one 
• 172481-12-8 [Ti(N-4-C₆H₄Me)Cl₂(pyridine)3] 

Downstream Products

• 400886-01-3 1,3,5-tris(aminomethyl)-2,4,6-tributylbenzene 
• 1195295-64-7 2,4,6-tri(1-butyl)aniline 
• 1384979-68-3 N,N'-bis[2,4,6-tri(1-butyl)phenyl]-1,4-diaza-1,3-diene 
• 1384979-71-8 N,N'-bis-(2,4,6-tri(1-butyl)phenyl)ethylenediamine 
• 1384979-73-0 N,N'-bis-(2,4,6-tri(1-butyl)phenyl)-4,5-dihydroimidazolium chloride 

Relevant academic research and scientific papers

Iron-catalyzed trimerization of terminal alkynes enabled by pyrimidinediimine ligands: A regioselective method for the synthesis of 1,3,5-substituted arenes

The development of pyrimidine-based analogues of the well-known pyridinediimine (PDI) iron complexes enables access to a functional-group-tolerant methodology for the catalytic trimerization of terminal aliphatic alkynes. Remarkably, in contrast to established alkyne trimerization protocols, the 1,3,5-substituted arenes are the main reaction products. Preliminary mechanistic investigations suggest that the enhanced π-acidity of the pyrimidine ring, combined with the hemilability of the imine groups coordinated to the iron center, facilitates this transformation. The entry point in the catalytic cycle is an isolable iron dinitrogen complex. The catalytic reaction proceeds via a 1,3-substituted metallacycle, which explains the observed 1,3,5-regioselectivity. Such a metallacycle could be isolated and represents a rare 1,3-substituted ferracycle obtained through alkyne cycloaddition.

Synthesis and Structures of Bis(indolyl)-Coordinated Titanium Dichlorido Complexes and Their Catalytic Application in the Cyclotrimerization of Alkynes

The impact of the terminal ligands on the titanium center on the coordination features of deprotonated 2,2′-bis(indolyl)methanes (henceforth: bis(indolyl)s) was studied via a structural comparison between {bis(indolyl)}Ti(NEt2)2 complexes and the corresponding dichlorido complexes. As a result, several flexible aspects of bis(indolyl) coordination were found. For example, it was revealed that an η1-coordinated indolyl moiety can change its coordination mode to coordination via the five-membered ring of indolyl when the terminal diethylamido ligands are replaced by chlorido ligands. Moreover, we found that the methoxy group in the central aromatic ring of the bis(indolyl) ligand can coordinate to the titanium center. The synthesized dichlorido complexes were applied for catalytic alkyne cyclotrimerization reactions, as Ti-based catalyst systems are less developed than Co-, Ni-, Ru-, Rh-, and Ir-based systems. During this study, the cyclotrimerization of HCCSiMe3 was found to preferentially produce the 1,3,5-form (1,3,5-form:1,2,4-form = 79:21), contrary to the typical trend of transition-metal-mediated alkyne cyclotrimerization, and the isolated yield (72%) is the highest among the known 1,3,5-favoring reactions using Ti-based catalyst systems. Furthermore, the reaction mechanism was experimentally verified to proceed through a typical stepwise mechanism involving monomeric species.

Cyclotrimerization of alkynes catalyzed by a self-supported cyclic tri-nuclear nickel(0) complex with α-diimine ligands

A cyclic tri-nuclear α-diimine nickel(0) complex [{Ni(μ-LMe-2,4)}3] (2) was synthesized from a “pre-organized”, trimerized trigonal LNiBr2-type precursor [Ni3(μ2-Br)3(μ3-Br)2(LMe-2,4)3]·Br (1; LMe-2,4 = [(2,4-Me2C6H3)NC(Me)]2). In complex 2, the α-diimine ligands not only exhibit the normal N,N′-chelating mode, but they also act as bridges between the Ni atoms through an unusual π-coordination of a C═N bond to Ni. Complex 2 is able to catalyze the cyclotrimerization of alkynes to form substituted benzenes in good yield and regio-selectivity for the 1,3,5-isomers, which is found to vary with the nature of the alkyne employed. This complex represents a convenient self-supported nickel(0) catalyst with no need for additional ligands and reducing agent.

Catalytic activity of a large Rhodium metallaborane towards the [2+2+2] cycloaddition of alkynes

Rhodadecaborane [6-(η5-C5Me5)-nido-6-RhB9H13] (1) was found to be able to catalyze the [2+2+2] cycloaddition of a series of terminal and internal alkynes to yield mixtures of 1,2,4- and 1,3,5-substituted benzene. The reactivity of compound 1 with alkynes demonstrates that decaborane based metallaborane can be used as the catalyst for [2+2+2] cycloaddition of alkynes. All compounds are characterized by NMR spectroscopy and MS spectrometry methods.

Alkyne [2 + 2 + 2] Cyclotrimerization Catalyzed by a Low-Valent Titanium Reagent Derived from CpTiX3 (X = Cl, O- i-Pr), Me3SiCl, and Mg or Zn

Inter-, partially intra-, and intramolecular [2 + 2 + 2] cycloadditions of alkynes were catalyzed by a low-valent titanium species generated in situ from the reduction of CpTi(O-i-Pr)3, CpTiCl3, or Cp?TiCl3 with Mg or Zn powder in the presence of Me3SiCl. The role of Me3SiCl as an additive in the reaction mechanism is discussed.

Oxidative nitrene transfer from azides to alkynes via Ti(ii)/Ti(iv) redox catalysis: Formal [2+2+1] synthesis of pyrroles

Catalytic oxidative nitrene transfer from azides with the early transition metals is rare, and has not been observed without the support of redox noninnocent spectator ligands. Here, we report the formal [2+2+1] coupling of azides and alkynes via TiII/TiIV redox catalysis from simple Ti halide imido precatalysts. These reactions yield polysubstituted N-alkyl pyrroles, including N-benzyl protected pyrroles and rare examples of very electron rich pentaalkyl pyrroles. Mechanistic analysis reveals that [2+2+1] reactions with bulky azides have different mechanistic features from previously-reported reactions using azobenzene as a nitrene source.

Generation of TiII alkyne trimerization catalysts in the absence of strong metal reductants

Low-valent TiII species have typically been synthesized by the reaction of TiIV halides with strong metal reductants. Herein we report that TiII species can be generated simply by reacting TiIV imido complexes with 2 equiv of alkyne, yielding a metallacycle that can reductively eliminate pyrrole while liberating TiII. In order to probe the generality of this process, TiII-catalyzed alkyne trimerization reactions were carried out with a diverse range of TiIV precatalysts.

Production of renewable lubricants: Via self-condensation of methyl ketones

Self-condensation of biomass-derived methyl ketones catalyzed by solid bases or acids produces corresponding cyclic trimers exclusively in excellent yields. Condensates containing 24-45 carbon atoms are shown to be suitable lubricant base-oils after the removal of residual unsaturation and oxygen. Properties of cycloalkanes produced from biomass are very similar to those of conventional lubricant base-oils. The process reported here offers an environmentally benign alternative to the current non-selective production of lubricant base-oils from α-olefins, and avoids the production of corrosive waste products.

Silica-supported tungsten carbynes (≡SiO)xW(≡CH)(Me)y (x = 1, y = 2; X = 2, y = 1): New efficient catalysts for alkyne cyclotrimerization

The activity of silica-supported tungsten carbyne complexes (≡SiO)xW(≡CH)(Me)y (x = 1, y = 2; x = 2, y = 1) toward alkynes is reported. We found that they are efficient precatalysts for terminal alkyne cyclotrimerization with high TONs. We also demonstrate that this catalyst species is active for alkyne cyclotrimerization without the formation of significant alkyne metathesis products. Additional DFT calculations highlight the importance of the W coordination sphere in supporting this experimental behavior.

Direct Evidence for a [4+2] Cycloaddition Mechanism of Alkynes to Tantallacyclopentadiene on Dinuclear Tantalum Complexes as a Model of Alkyne Cyclotrimerization

A dinuclear tantalum complex, [Ta2Cl6(μ-C4Et4)] (2), bearing a tantallacyclopentadiene moiety, was synthesized by treating [(η2-EtC≡CEt)TaCl3(DME)] (1) with AlCl3. Complex 2 and its Lewis base adducts, [Ta2Cl6(μ-C4Et4)L] (L=THF (3a), pyridine (3b), THT (3c)), served as more active catalysts for cyclotrimerization of internal alkynes than 1. During the reaction of 3a with 3-hexyne, we isolated [Ta2Cl4(μ-η4:η4-C6Et6)(μ-η2:η2-EtC≡CEt)] (4), sandwiched by a two-electron reduced μ-η4:η4-hexaethylbenzene and a μ-η2:η2-3-hexyne ligand, as a product of an intermolecular cyclization between the metallacyclopentadiene moiety and 3-hexyne. The formation of arene complexes [Ta2Cl4(μ-η4:η4-C6Et4Me2)(μ-η2:η2-Me3SiC≡CSiMe3)] (7b) and [Ta2Cl4(μ-η4:η4-C6Et4RH)(μ-η2:η2-Me3SiC≡CSiMe3)] (R=nBu (8a), p-tolyl (8b)) by treating [Ta2Cl4(μ-C4Et4)(μ-η2:η2-Me3SiC≡CSiMe3)] (6) with 2-butyne, 1-hexyne, and p-tolylacetylene without any isomers, at room temperature or low temperature were key for clarifying the [4+2] cycloaddition mechanism because of the restricted rotation behavior of the two-electron reduced arene ligands without dissociation from the dinuclear tantalum center.