133844-84-5

Usage

Synthesis Reference(s)

Synthesis, p. 589, 1996 DOI: 10.1055/s-1996-4265

Upstream product

• 115-19-5 2-methyl-but-3-yn-2-ol 
• 4298-52-6 2-ethynyl-thiophene 
• 67-64-1 acetone 
• 3437-95-4 2-Iodothiophene 
• 50838-78-3 2,6-dimethyl-5-methylene-hept-3-yne-2,6-diol 
• 1003-09-4 2-bromothiophene 

Downstream Products

• 1360703-69-0 (Z)-3-benzoyl-5,5-dimethyl-4-(thiophene-2-ylmethylene)oxazolidin-2-one 
• 16900-51-9 1,4-bis(2-thienyl)butadiyne 
• 4805-17-8 2-(phenylethynyl)thiophene 
• 93297-81-5 2,5-(2,2'-dithienyl)diethynyl-thiophene 

Relevant academic research and scientific papers

Heteroaryl functionalised diacetylenes: Preparation and solid-state reactivity

Diacetylenes are known to undergo solid-state topochemical polymerisation to give polydiacetylenes. The reactivity of the monomer is controlled by the arrangement of the molecules in the crystal lattice wherein certain parametric conditions must be met for 1,4-addition to proceed. In the present paper, we investigated the structure-reactivity relationship of a class of diacetylene monomers. Heteroaryl moieties such as thiophene, benzo[b]thiophene and quinoline as one or both directly bound side groups of a diacetylene backbone were used. Thus various symmetrical as well as unsymmetrical diacetylenes were prepared and characterised. The solid-state polymerisation behaviour of these diacetylenes was studied in the light of their single-crystal X-ray structure. It was found that in order to react in the solid state, the diacetylenes must have the required lattice parameters. However, even when the required lattice parameters are met, the diacetylene monomers do not necessarily undergo solid-state 1,4-addition polymerisation, implying the existence of further controlling factors to determine reactivity.

An improved procedure for the preparation of aryl- and hetarylacetylenes

A number of relatively volatile acetylenes RC ≡ CH (R = aryl or hetaryl) have been prepared with high yields by heating a mixture of the corresponding alcohols RC ≡ CC(CH3)2OH and paraffin oil with small amounts of powdered potassium hydroxide in vacuum. The alcohols were obtained by Pd/Cu-catalyzed cross coupling of aryl or hetaryl halides RX (X = Br, in one case I) with the commercially available HC ≡ CC(CH3)2OH.

Thermal behavior of diynes with formally conjugated heteroaromatic sidegroups

Diynes with heteroaromatic sidegroups directly linked to the acetylenic backbone were found to show liquid crystalline behaviour upon heating. Thus, 1,4-di(2-thienyl)-1,3-butadiyne, 1,4-di(3-thienyl)-1,3-butadiyne, 1,4-di(3- benzo[b]thienyl)-1,3-butadiyne, 1-(3-quinolyl)-4-(2-thienyl)-1,3-butadiyne, 1-(3-quinolyl)-4-(3-thienyl)-1,3-butadiyne, and 5-(2-thienyl)-2,4-pentadiyne- 1-ol were investigated for their thermal behavior. These diynes also underwent polymerization in their liquid crystalline state, although the polymers so formed did not show liquid crystalline behavior. It was found that the S-atom of the heteroaromatic moieties tends to play a role in making the diynes show liquid crystalline behavior. Differential scanning calorimetry, thermogravimetric analysis and hot stage microscopy were used to investigate the liquid crystalline nature of the diynes. All of them showed a nematic liquid crystalline phase upon annealing, whereas smectic phase was totally absent.

Nanosized Pd(0)-arabinogalactan composites as catalysts in the Sonogashira reaction

Zero-valent palladium nanoparticles stabilized by arabinogalactan polysaccharide matrix were successfully used for the first time as phosphine-free catalyst in the cross-coupling of terminal alkynes with aryl and hetaryl halides.

Facile synthesis of substituted thiophenes via Pd/C-mediated sonogashira coupling in water

The first successful Pd/C-mediated Sonogashira coupling of iodothiophene with terminal alkynes in water is described here. Pd/C-CuI-PPh3 was found to be an efficient catalyst system for this coupling reaction. Using this economic and reliable process a variety of acetylenic thiophenes with a wide range of functional groups were prepared in good yields. Synthetic applications and in vitro anticancer properties of some of the compounds synthesized are described.

Rhodium-catalyzed oxidative coupling of benzoic acids with propargyl alcohols: An efficient access to isocoumarins

An efficient protocol of Rh(III)-catalyzed oxidative cyclization of benzoic acids with propargyl alcohols to give substituted isocoumarins under mild conditions was reported. A variety of substrates were applied in this reaction in yields up to 89%.

Bimetal Cooperatively Catalyzed Arylalkynylation of Alkynylsilanes

An unprecedented Pd/Rh cooperatively catalyzed arylalkynylation of alkynylsilanes was developed to merge an alkynylidene moiety with benzosilacycle. These silaarenes possess a particular aggregation-induced emission behavior. Mechanistic investigations demonstrate that the relay trimetallic transmetalation plays a pivotal role in governing this transformation.

Cleavage of C–C and C–O Bonds to Form C–C Bonds: Direct Cross-Coupling between Acetylenic Alcohols and Benzylic Carbonates

A palladium-catalyzed cross-coupling reaction between C(sp) and C(sp3) centers was achieved in excellent yields via C–C bond cleavage and C–O bond cleavage. This procedure uses relatively stable acetylenic alcohols as reactants instead of unsta

Highly Efficient Synthesis of Multi-Substituted Allenes from Propargyl Acetates and Organoaluminum Reagents Mediated by Palladium

A simple and mild catalytic S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents is reported. The S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents mediated by Pd(PhP 3) 2 Cl 2 (1 mol%)/PPh 3 (2 mol%)/K 2 CO 3 in tetrahydrofuran at 60 °C for 3-4 hours afforded the corresponding multi-substituted allenes in good yields (up to 94%) with high selectivities (up to 99%). The process was simple and easily performed, which offers an efficient method to synthesize the multi-substituted allene derivatives.

Gold-Catalyzed [4+2]- and [3+3]-Annulations of Ynamides with 1-Yn-3-ols to Access Six-Membered Carbocycles and Oxacycles via Three Distinct Cyclizations

Three distinct strategies for catalytic annulations between ynamides and 1-yn-3-ols are described; the resulting carbo- and heterocycles were produced efficiently in one-pot operations using a gold catalyst. The chemoselectivities of these annulations are controlled by variations of the substituents of the ynamides and the 1-yn-3-ols. This reaction sequence involves initial alkoxylations of ynamides, followed by Claisen rearrangement of propargylic enol ethers, and ends with 6-endo-trig cyclizations of 1-allenyl-5-amide intermediates. Among these cascade annulations, the cyclizations of 5-allenyl-1-amides to yield 5,6-dihydro-2-pyranones and 6-alkylenecyclohex-2-ene-1-carboxamides are unprecedented in the literature. (Figure presented.).