95969-89-4Relevant academic research and scientific papers
Z-Selective phosphine promoted 1,4-reduction of ynoates and propynoic amides in the presence of water
Drikermann, Denis,Kupfer, Stephan,Seifert, Fabian,Steinmetzer, Johannes,Vilotijevic, Ivan,Zi, You
supporting information, p. 6092 - 6097 (2021/07/21)
Phosphine-mediated reductions of substituted propynoic esters and amides in the presence of water yield the partially reduced α,β-unsaturated esters and amides with highZ-selectivity. The competitivein situ ZtoE-isomerization of the product in some cases lowers theZtoEratios of the isolated α,β-unsaturated carbonyl products. Reaction time and the amounts of phosphine and water in the reaction mixture are the key experimental factors which control the selectivity by preventing or reducing the rates ofZ- toE-product isomerization. Close reaction monitoring enables isolation of theZ-alkenes with high selectivities. The computational results suggest that the reactions could be highlyZ-selective owing to the stereoselective formation of theE-P-hydroxyphosphorane intermediate.
N-triflyl-propiolamides: Preparation and transamidation reactions
Fiore, Vito A.,Maas, Gerhard
, p. 3586 - 3595 (2019/05/27)
N-Trifluoromethylsulfonyl-propiolamides have been prepared by two methods: a) N-triflation of secondary acetylenic carboxanilides, prepared in two steps from terminal alkynes, with triflic anhydride (Tf2O) and b) from terminal alkynes and an aryl or alkyl isocyanate followed by Tf2O in a consecutive one-pot reaction. The title compounds are bench-stable and insensitive to water and alcohols but amenable to transamidation reactions with a wide range of amine nucleophiles. Conversely, they are excellent reagents for the propynoylation of ammonia, primary and secondary amines, anilines, and hydrazines.
Phosphine-mediated partial reduction of alkynes to form both (E)- and (Z)-alkenes
Pierce, Brett M.,Simpson, Brittany F.,Ferguson, Kane H.,Whittaker, Rachel E.
supporting information, p. 6659 - 6662 (2018/09/29)
A mild, phosphine-mediated partial reduction of alkynyl carbonyls to the corresponding alkenes was developed. Tuning of the reaction conditions led to either the (E)- or (Z)-diastereomer with high selectivity. A range of alkynyl esters, amides, and ketones were reduced to form alkenes in good to high yields and with excellent functional group tolerance.
Efficient synthesis of alkynyl amides via aminocarbonylation of iodoalkynes
Szuroczki, Péter,Boros, Borbála,Kollár, László
, p. 6129 - 6136 (2018/09/14)
Iodoethynylbenzene as iodoalkyne model compound was aminocarbonylated with tert-butylamine under carbon monoxide atmosphere in the presence of in situ palladium(0) catalysts. The formation of the unsaturated carboxamide (alkynyl amide) is always accompanied by that of the Glaser coupling product, diphenylbutadiyne. The yield of the amide-forming reaction was optimised by the systematic variation of the phosphine ligand, carbon monoxide pressure and temperature. The scope of the reaction was investigated by using various primary and secondary amines including amino acid methyl esters as N-nucleophiles. 17α-(Iodoethynyl)-testosterone was also functionalised by using this methodology providing the corresponding 17α-(carboxamidoethynyl)-testosterone derivatives in up to 96% yields. The reaction was extended to 1-(iodoethynyl)cyclohex-1-ene and 1-iodohex-1-yne. Ethyl iodopropiolate gave the enamine type product by the addition of amine to the alkyne functionality which was formed from the iodoalkyne via deiodination under standard aminocarbonylation conditions. The bromo analogue, bromoethynylbenzene has shown lower reactivity than the corresponding iodo derivative.
Sequential protocol for C(sp)–H carboxylation with CO2: KOtBu-catalyzed C(sp)–H silylation and KOtBu-mediated carboxylation
Yu, Bo,Yang, Peng,Gao, Xiang,Yang, Zhenzhen,Zhao, Yanfei,Zhang, Hongye,Liu, Zhimin
, p. 449 - 456 (2018/02/06)
CO2 incorporation into C–H bonds is an important and interesting topic. Herein a sequential protocol for C(sp)–H carboxylation by employing a metal-free C–H activation/catalytic silylation reaction in conjunction with KOtBu-mediated carboxylation with CO2 was established, in which KOtBu catalyzes silylation of terminal alkynes to form alkynylsilanes at low temperature, and simultaneously mediates carboxylation of the alkynesilanes with atmospheric CO2. Importantly, the carboxylation further promotes the silylation, which makes the whole reaction proceed very rapidly. Moreover, this methodology is simple and scalable, which is characterized by short reaction time, wide substrate scope, excellent functional-group tolerance and mild reaction conditions, affording a range of corresponding propiolic acid products in excellent yields in most cases. In addition, it also allows for a convenient 13C-labeling through the use of 13CO2.
CsF-promoted carboxylation of aryl(hetaryl) terminal alkynes with atmospheric CO2 at room temperature
Yu,Yang,Gao,Yang,Zhao,Zhang,Liu
supporting information, p. 9250 - 9255 (2017/08/29)
A CsF-promoted carboxylation of aryl(hetaryl) terminal alkynes with atmospheric CO2 in the presence of trimethylsilylacetylene was developed to give functionalized propiolic acid products at room temperature. A wide range of propiolic acids bearing functional groups was successfully obtained in good to excellent yields. Mechanistic studies demonstrate that in the carboxylation process the alkynylsilane intermediate was first in situ generated, which was then trapped by CO2, giving rise to the corresponding functionalized propiolic acids after acidification. The advantages of this approach include avoiding use of transition-metal catalysts, wide substrate scope together with excellent functional group tolerance, ambient conditions and a facile work-up procedure.
Palladium-Catalyzed Oxidative N-Dealkylation/Carbonylation of Tertiary Amines with Alkynes to α,β-Alkynylamides
Mane, Rajendra S.,Bhanage, Bhalchandra M.
, p. 4974 - 4980 (2016/07/06)
The first highly effective Pd/C-catalyzed oxidative N-dealkylation/carbonylation of various aliphatic as well as cyclic tertiary amines with alkynes has been described. The selective sp3 C-N bond activation of tertiary amines at the less steric side using O2 as a sole oxidant and a plausible reaction pathway for the reaction are discussed. The general and operationally simple methodology provides an alternative for the synthesis of a wide range of alk-2-ynamide derivatives under mild conditions. The present protocol is ecofriendly and practical, and it shows significant recyclability.
Palladium-catalyzed oxidative aminocarbonylation by decarboxylative coupling: Synthesis of alkynyl amides
Hwang, Jinil,Choi, Jinseop,Park, Kyungho,Kim, Wonyoung,Song, Kwang Ho,Lee, Sunwoo
supporting information, p. 2235 - 2243 (2015/04/14)
Alkynyl amides were synthesized from a palladium-catalyzed coupling reaction of alkynyl carboxylic acids and amines under carbon monoxide. The reaction was conducted with palladium(II) acetate (5 mol-%) and silver(I) oxide (1.0 equiv.) in acetonitrile at 80 °C for 1 h. This method provides good to moderate product yields and good functional group tolerance towards ketone, ester, and nitrile groups.
One-pot tandem hydrophenylation and ionic hydrogenation of 3-phenylpropynoic acid derivatives under superelectrophilic activation
Nilov, Denis I.,Vasilyev, Aleksander V.
supporting information, p. 5714 - 5717 (2015/09/29)
The reactions of esters and amides of 3-phenylpropynoic acid with strong Lewis acids AlX3 (X = Cl, Br) or conjugate Br?nsted-Lewis superacids HX-AlX3 (X = Cl, Br) in benzene and cyclohexane at room temperature afforded 3,3-diphenylpropanoic acid derivatives in up to 94% yield. This tandem reaction of the acetylene bond proceeded by hydrophenylation followed by ionic hydrogenation.
Palladium-catalysed Hiyama cross-coupling reaction of alkynyl halides with aryltrialkoxysilanes under aerobic conditions
Tang, Jiansheng,Guo, Cancheng
, p. 123 - 127 (2014/03/21)
A palladium-catalysed Hiyama cross-coupling reaction of alkynyl halides with aryltrialkoxysilanes has been developed. Catalysed by bis(dibenzylideneacetone)palladium and in the presence of silver fluoride and potassium bicarbonate, a variety of alkynyl halides (I, Br and Cl), whether electron-deficient or electron-rich, underwent the cross-coupling reaction with aryltrialkoxysilanes at room temperature to afford the corresponding alkynes in moderate to good yields.
