81532-79-8

Upstream product

• 118520-70-0 1-copper(I) (4-bromophenyl)ethyne 
• 75-36-5 acetyl chloride 
• 129725-59-3 4-(4-bromophenyl)-3-butyn-2-ol 
• 766-96-1 4-bromo-1-ethynylbenzene 
• 141-78-6 ethyl acetate 
• 589-87-7 1,4-bromoiodobenzene 
• 16116-78-2 (4-bromophenyl)(trimethylsilyl)acetylene 

Downstream Products

• 129725-59-3 4-(4-bromophenyl)-3-butyn-2-ol 
• 1189116-42-4 2-(4-bromobenzylidene)-1-cyano-3-oxo-5-phenylcyclopentanecarboxylic acid ethyl ester 

Relevant academic research and scientific papers

Synthesis of (: Z)-β-halo α,β-unsaturated carbonyl systems via the combination of halotrimethylsilane and tetrafluoroboric acid

A convenient and broadly applicable method for the hydrohalogenation of ynones is described, by the combination of halotrimethylsilanes and tetrafluoroboric acid. Practically, one equivalent of HX (Br?nsted acid) and BF3 (Lewis acid) is smoothly generated, which activates the carbonyl compounds. Through this protocol, 42 examples of (Z)-β-halovinyl carbonyl compounds (Cl, Br and I) were obtained, in good yields and high stereoselectivity having 2-MeTHF as a solvent.

Iridium-Catalyzed Asymmetric Transfer Hydrogenation of Alkynyl Ketones Using Sodium Formate and Ethanol as Hydrogen Sources

A green and efficient iridium-catalyzed asymmetric transfer hydrogenation of alkynyl ketones to chiral propargylic alcohols has been developed. By using sodium formate and ethanol as hydrogen sources, a series of alkynyl ketones were hydrogenated by chira

Gold-catalyzed Fluorination of Alkynyl Esters and Ketones: Efficient Access to Fluorinated 1,3-Dicarbonyl Compounds

We developed an efficient synthesis of 2-fluoro-1,3-dicarbonyl compounds using readily available alkynyl ketones or esters as starting material. The key step is the insertion of hydrogen fluoride (HF) to the gold carbene intermediate generated from cationic gold catalyzed addition of N-oxides to alkynyl ketones or esters. This method gives excellent chemical yields and regioselectivity with good functional group tolerance. (Figure presented.).

Phosphane-Catalyzed [3+3] Annulation of C,N-Cyclic Azomethine Imines with Ynones: A Practical Method for Tricyclic Dinitrogen-Fused Heterocycles

A phosphane-catalyzed [3+3] annulation of azomethine imines with ynones has been developed. Under mild reaction conditions, the reaction proceeds smoothly to afford tricyclic dinitrogen-fused heterocyclic compounds in moderate to excellent yields with moderate to excellent stereoselectivies. Using a chiral phosphine as the catalyst, the reaction could work to give the cycloadduct in moderate yield with moderate enantioselectivity. (Figure presented.) .

Biocatalytic asymmetric synthesis of optically pure aromatic propargylic amines employing ω-transaminases

The asymmetric reductive bio-amination of prochiral aromatic propargyl ketones led to the corresponding amines in optically pure form (ee>99%). The (R)- as well as the (S)-enantiomers of the propargylic amines were obtained, employing either (R)-selective ω-transaminases (ω-TAs) originating from Arthrobacter sp. and Aspergillus terreus or an (S)-selective ω-TA from Chromobacterium violaceum. The product propargylic amines were obtained with high conversions (up to 99%). To simplify product isolation, protection of the free amino group to the corresponding acetamides or benzamides was performed without loss of optical puritiy. The final products were isolated in moderate to good yields (33-67% over two steps) in optical pure form without additional purification steps. Although propargyl ketones are described in the literature to be irreversible inhibitors for aminotransferases, suitable ω-transaminases were identified for the amination of these compounds.

Aerobic oxidation of propargylic alcohols to αβ,-unsaturated alkynals or alkynones catalyzed by fe(NOH, TEMPO and sodium chloride in toluene

A practical aerobic oxidation of propargylic alcohols using Fe(NOH, TEMPO and sodium chloride in toluene at room temperature was applied to various type of propargylic alcohols affording ,-unsaturated alkynals or alkynones in good to excellent yields. This protocol could be applied in academic laboratories as well as in industrial-scale production.

Enantioselective synthesis of both enantiomers of various propargylic alcohols by use of two oxidoreductases

The oxidoreductases Lactobacillus brevis alcohol dehydrogenase (LBADH) and Candida parapsilosis carbonyl reductase (CPCR) are suitable catalysts for the reduction of ketones to afford enantiopure sec. alcohols. A broad variety of alkynones (1, 3, and 5) are accepted as substrates and the corresponding propargylic alcohols (2, 4, and 6) are obtained in good yield and excellent enantiomeric excess. By changing the steric demand of the substituents the ee values can be adjusted and even the configurations of the products can be altered.

Polymer-supported selenol esters as useful acylating reagents. Application to α, β-acetylenic ketones synthesis

Three novel polystyrene supported selenol esters were synthesized and used as acyl transfer agents to prepare α, β-acetylenic ketones by reaction with alkynylcoppers.