6142-95-6

Usage

Chemical Properties

CLEAR COLOURLESS TO YELLOW LIQUID

Preparation

To a flask equipped with a 12-in. Vigreux column and distillation head is added 74.0 gm (0.50 mole) of triethyl orthoformate, 51.0 gm (0.50 mole)of phenylacetylene, and 3.0 gm of zinc iodide* catalyst. The flask must first be heated to 135°C before ethanol starts to reflux. The ethanol distillate (26.4 gm) boiling at 65°-88°C is removed over a period of 1 hr while the temperature of the reaction mixture is raised to 200°-210°C. The reaction mixture is cooled and filtered, the precipitate washed with 5 ml of ether and the ether combined with the filtrate is distilled to afford 73-80 gm (72-78%), b.p. 99-100°C (2.0 mm Hg). The IR spectrum showed absorption at 4.5-μ (—C=C—) and 9.0-μ region ( - C — O ).

Synthesis Reference(s)

The Journal of Organic Chemistry, 49, p. 2031, 1984 DOI: 10.1021/jo00185a045

InChI:InChI=1/C13H16O2/c1-3-14-13(15-4-2)11-10-12-8-6-5-7-9-12/h5-9,13H,3-4H2,1-2H3

Upstream product

• 6738-06-3 phenylethynylmagnesium bromide 
• 122-51-0 orthoformic acid triethyl ester 
• 591-50-4 iodobenzene 
• 10160-87-9 Propiolaldehyde diethyl acetal 
• 14444-77-0 diethyl phenyl orthoformate 
• 925-90-6 ethylmagnesium bromide 
• 536-74-3 phenylacetylene 
• 64-17-5 ethanol 
• 115525-21-8 gem-2-bromo-2-phenyl-1,1-dichlorocyclopropane 
• 178425-56-4 1,1,2-tribromo-2-phenylcyclopropane 
• 161806-75-3 (benzotriazol-1-yl)diethoxymethane 
• 2579-22-8 Phenylpropargyl aldehyde 
• 98-81-7 1-bromovinylbenzene 
• 2996-92-1 phenyl trimethylsiloxane 

Downstream Products

• 18322-09-3 (E)-3,3,3-Triethoxy-1-phenylpropene 
• 1945-27-3 1-Phenyl-3,5,5-triethoxy-4-brompentin-⁽¹⁾ 
• 14499-25-3 2-Acetyl-3-ethoxy-5-phenyl-pent-4-insaeureethylester 
• 131202-82-9 3-Diethoxymethyl-1-methyl-2-phenyl-1H-1-aza-phenalene 
• 109481-92-7 (Z)-5-Phenyl-2-trimethylsilanylmethyl-pent-2-en-4-ynoic acid ethyl ester 
• 80393-18-6 1,1,3-triethoxy-2-gem-dichlorocyclopropyl-5-phenyl-4-pentyne 
• 13524-09-9 (3,3-dichloroprop-1-yn-1-yl)benzene 
• 138777-55-6 1-bromo-1-chloro-3-phenylprop-2-yne 
• 138777-54-5 1,1-dibromo-3-phenylprop-2-yne 
• 102259-10-9 ((E)-1,2-Dibromo-3,3-diethoxy-propenyl)-benzene 
• 149726-72-7 3-phenylpropanal-2,2,3,3-d4 
• 183614-20-2 1-(1,2,4-triazol-1-yl)-3-phenylpropargyl ethyl ether 
• 251481-79-5 rel-(2R,3S,4R)-4,5-dimethyl-2-phenylethylnyl-1,3-dioxolane 
• 195374-93-7 rel-(2S,3S,4R)-4,5-dimethyl-2-phenylethylnyl-1,3-dioxolane 

Relevant academic research and scientific papers

THE SYNTHESIS OF ACETYLENIC ACETALS

Zinc chloride on silica gel is an active catalyst for the condensation of ethyl orthoformate with thermal acetylenes.

Lewis-acid-catalyzed asymmetric alkynylation of alkynyl 1,2-diketones: Controllable formation of 3(2 H)-furanones and α-hydroxy ketones

We report the highly regio- and enantioselective alkynylation of alkynyl 1,2-diketones under Lewis acid catalysis, leading to the formation of a series of biologically important 3(2H)-furanones with high to excellent ee values. Moreover, a slight change of the reaction conditions produces a range of highly functionalized α-hydroxy ketones with a high level of enantioselectivity. A variety of further transformations can be easily achieved, demonstrating the synthetic potential of this protocol.

Regiodivergent Hydration-Cyclization of Diynones under Gold Catalysis

Skipped diynones, efficiently prepared from biomass-derived ethyl lactate, undergo a tandem hydration-oxacyclization reaction under gold(I) catalysis. Reaction conditions have been developed for a switchable process that allows selective access to 4-pyrones or 3(2H)-furanones from the same starting diynones. Further application of this methodology in the total synthesis of polyporapyranone B was demonstrated.

Blue light photoredox-catalysed acetalation of alkynyl bromides

Herein, we report an organo-photoredox-based protocol using 2,2-diethoxyacetic acid as the acetal source to achieve acetalation of alkynyl bromides to afford various alkynyl acetal products. In addition to arylethynyl bromides, substrates bearing heteroaryl rings (thiophene, pyridine, and indole) smoothly gave the corresponding acetalation products. This mild protocol has potential utility for the synthesis of aldehydes by further protonization.

P-Stereogenic Phosphines Directed Copper(I)-Catalyzed Enantioselective 1,3-Dipolar Cycloadditions

A new pair of P-stereogenic ligands with multiple chiral centers were synthesized and used in the copper(I)-catalyzed enatioselective [3 + 2] cycloaddition of iminoesters with alkenes. A variety of highly functionalized pyrrolidines were obtained in excellent yield and enatioselectivity. This is the first example of a pair of P-stereogenic ligands working as pseudoenantiomers to tune the enantio- and diastereoselective 1,3-dipolar cycloaddition, and providing a pair of enantiomerically pure pyrrolidines, respectively.

Synthesis of 1,3-dioxacyclan-2-yl-substituted 1,2,3-triazoles

A new method for preparing 4-(1,3-dioxacyclan-2-yl)-5-phenyl-1,2,3-triazoles in 30–75% yields has been developed on the basis of azide–alkyne cycloaddition to 2-phenylethinyl-1,3-dioxacyclanes. It has been shown that the best results are achieved when the reaction is carried out at 150–155°C in DMSO.

N-Heterocyclic Carbene-Catalyzed Umpolung of Alkynyl 1,2-Diketones

The umpolung of alkynyl 1,2-diketones via N-heterocyclic carbene (NHC) catalysis was achieved for the first time, allowing the rapid access to a large variety of synthetically and pharmaceutically important α-pyrones under very mild conditions. A completely new NHC-catalyzed umpolung pattern involving an O-acylated allenolate as the key intermediate was proposed. Moreover, an unprecedented reaction pathway, featured by a series of group migrations and new bond formation, was postulated to demonstrate the formation of the products. (Figure presented.).

Synthesis of 1,5-disubstituted (E)-pent-2-en-4-yn-1-ones

The condensation of 3-arylpropynals with aryl methyl ketones in the presence of sodium hydroxide in 50% aqueous ethanol at 0°C (Claisen-Schmidt reaction) afforded up to 89% of the corresponding (E)-1,5-diarylpent-2-en-4-yn- 1-ones. The E configuration of the double C=C bond and cis conformation of the enone fragment in the products in crystal and CDCl3 solution were determined by X-ray analysis and 1H NMR spectroscopy.

Palladium-catalyzed cross-coupling reaction of aryl trimethoxysilanes with terminal alkynes

A palladium-catalyzed cross-coupling reaction of aryl trimethoxysilanes with terminal alkynes was described. Thus, di-substituted alkynes were prepared in moderate to good yields. The electron-deficient terminal alkynes also worked well in the procedure.

Stereoselective synthesis of (E)-α,β-unsaturated esters via carbene-catalyzed redox esterification

Stereoselective, carbene-mediated redox esterification of alkynyl aldehydes provides mild and atom economical access to (E)-configurated, α,β-unsaturated carboxylic esters. The organocatalytic method relies on the generation of activated carboxylates via extended/conjugated umpolung in the presence of catalytic amounts of carbene precursor and base.