- H2O2-mediated room temperature synthesis of 2-arylacetophenones from arylhydrazines and vinyl azides in water
-
An environmentally benign, cost-efficient and practical methodology for the room temperature synthesis of 2-arylacetophenones in water has been discovered. The facile and efficient transformation involves the oxidative radical addition of arylhydrazines with α-aryl vinyl azides in the presence of H2O2 (as a radical initiator) and PEG-800 (as a phase-transfer catalyst). From the viewpoint of green chemistry and organic synthesis, the present protocol is of great significance because of using cheap, non-toxic and readily available starting materials and reagents as well as amenability to gram-scale synthesis, which provides an attractive strategy to access 2-arylacetophenones.
- Luo, Mengqiang,Zhang, Yaohong,Fang, Ping,Li, Yan,Qi, Chenze,Li, Yong,Shen, Runpu,Cheng, Kai,Wang, Hai
-
supporting information
p. 630 - 635
(2022/02/01)
-
- Iron-Catalyzed Enantioselective Radical Carboazidation and Diazidation of α,β-Unsaturated Carbonyl Compounds
-
Azidation of alkenes is an efficient protocol to synthesize organic azides which are important structural motifs in organic synthesis. Enantioselective radical azidation, as a useful strategy to install a C-N3 bond, remains challenging due to the inherently instability and unique structure of radicals. Here, we disclose an efficient enantioselective radical carboazidation and diazidation of α,β-unsaturated ketones and amides catalyzed by chiral N,N′-dioxide/Fe(OTf)2 complexes. An array of substituted alkenes was transformed to the corresponding α-azido carbonyl derivatives in good to excellent enantioselectivities, benefiting the preparation of chiral α-amino ketones, vicinal amino alcohols, and vicinal diamines. Control experiments and mechanistic studies proved the radical pathway in the reaction process. The DFT calculations showed that the azido transferred to the radical intermediate via an intramolecular five-membered transition state with the internal nitrogen of the Fe-N3 species.
- Dong, Shunxi,Feng, Xiaoming,He, Jun,Liu, Wen,Liu, Xiaohua,Pu, Maoping,Wu, Yun-Dong,Zhang, Tinghui
-
supporting information
p. 11856 - 11863
(2021/08/16)
-
- Ring size and nothing else matters: unusual regioselectivity of alkyne hydration by NHC gold(i) complexes
-
We have investigated the role of ring sizes and substituents in NHC ligands in some (NHC)Au(i) complexes in the hydration of internal alkynes. Despite the fact that using (NHC)Au(i) complexes in the hydration of diarylacetylenes leads to Markovnikov-type products, the precise tuning of ligands allows changing the regioselectivity in arylalkylacetylene hydration to the anti-Markovnikov-type.
- Ageshina, Alexandra A.,Asachenko, Andrey F.,Chesnokov, Gleb A.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Philippova, Anna N.,Rzhevskiy, Sergey A.,Topchiy, Maxim A.
-
supporting information
p. 5686 - 5689
(2021/06/16)
-
- Exploiting Aryl Mesylates and Tosylates in Catalytic Mono-α-arylation of Aryl- and Heteroarylketones
-
The first general palladium catalyst for the catalytic mono-α-arylation of aryl- and heteroarylketones with aryl mesylates and tosylates is described. The newly developed indolyl-derived phosphine ligand L7 has been identified to promote this reaction eff
- Fu, Wai Chung,So, Chau Ming,Yuen, On Ying,Lee, Irene Toi Chuk,Kwong, Fuk Yee
-
supporting information
p. 1872 - 1875
(2016/05/19)
-
- Catalyst-controlled highly selective coupling and oxygenation of olefins: A direct approach to alcohols, ketones, and diketones
-
Oxygen? That's radical! A method for the direct synthesis of substituted alcohols, ketones, and diketones through a catalyst-controlled highly chemoselective coupling and oxygenation of olefins has been developed. The method is simple and practical, can be switched by the selection of different catalysts, and employs molecular oxygen as both an oxidant and a reagent. Copyright
- Su, Yijin,Sun, Xiang,Wu, Guolin,Jiao, Ning
-
supporting information
p. 9808 - 9812
(2013/09/23)
-
- Deoxybenzoins from Stille carbonylative cross-couplings using molybdenum hexacarbonyl
-
Stille-type carbonylative cross-couplings, employing palladium catalysis and Mo(CO)6 as the carbon monoxide carrier, were used for the preparation of deoxybenzoins. Straightforward transformations were conveniently performed in closed vessels at 100 °C, providing the products in good yields. Benzyl bromides and chlorides were used as coupling partners with aryl and heteroaryl stannanes. This mild three-component carbonylation employs the destabilizing agent DBU to promote smooth release of carbon monoxide from Mo(CO)6, which made this protocol operationally simple and minimized the formation of Stille diarylmethane products.
- S?vmarker, Jonas,Lindh, Jonas,Nilsson, Peter
-
supporting information; experimental part
p. 6886 - 6889
(2011/03/17)
-
- Direct preparation of benzylic manganese reagents from benzyl halides, sulfonates, and phosphates and their reactions: Applications in organic synthesis
-
The use of highly active manganese (Mn)*, prepared by the Rieke method, was investigated for the direct preparation of benzylic manganese reagents. The oxidative addition of the highly active manganese to benzylic halides was easily completed under mild conditions. Moreover, benzylic manganese sulfonates and phosphates were prepared by direct oxidative addition of Mn* to the carbon-oxygen bonds of benzylic sulfonates and phosphates. The resulting benzylic manganese reagents were found to undergo cross-coupling reactions with a variety of electrophiles. Most of these reactions were carried out in the absence of any transition metal catalyst under mild conditions. In addition, the use of highly active manganese was also studied for preparation of homo-coupled products of functionalized benzyl halides without transition metal catalysts. These useful approaches provided not only a facile synthetic route to the preparation of resoricinolic lipids but a facile synthesis of functionalized 4-benzylpyridines by regioselective and chemo selective γ-addition of benzylic group to N-alkoxycarbonylpyridinum salts.
- Suh, YoungSung,Lee, Jun-Sik,Kim, Seoung-Hoi,Rieke, Reuben D.
-
-
- Benzylic Manganese Halides, Sulfonates, and Phosphates: Preparation, Coupling Reactions, and Applications in Organic Synthesis
-
The use of highly active manganese, prepared by the Rieke method, for the direct preparation of benzylic manganese reagents was investigated. The oxidative addition of the highly active manganese (Mn*) to benzylic halides was easily completed under mild conditions. More importantly, benzylic manganese sulfonates and phosphates were prepared by direct oxidative addition of Mn* to the carbon-oxygen bonds of benzylic sulfonates and phosphates. The resulting benzylic manganese reagents were found to undergo cross-coupling reactions with a variety of electrophiles. The majority of these reactions were carried out in the absence of any transition metal catalyst under mild conditions. This approach also provided a facile synthetic route to the preparation of resorcinolic lipids.
- Kim, Seung-Hoi,Rieke, Reuben D.
-
p. 2322 - 2330
(2007/10/03)
-
- Nickel-catalyzed direct electrochemical cross-coupling between aryl halides and activated alkyl halides
-
The electrochemical reduction of a mixture of aryl halides and activated alkyl halides in DMF in the presence of catalytic amount of NiBr2bipy leads to cross-coupling products in good to high yields. The method applies to the synthesis of α-aryl ketones, α-aryl esters, and allylated compounds from readily available organic halides. Optimization of the process has been obtained by slowly adding the most reactive organic halide (usually the activated alkyl halide) during the electrolysis which is best conducted at 70 °C when aryl bromides are involved.
- Durandetti, Muriel,Nedelec, Jean-Yves,Perichon, Jacques
-
p. 1748 - 1755
(2007/10/03)
-
- A novel method of arylation of α-chloroketones
-
α-Arylated ketones were obtained in moderate to good yields by one-step electroreductive coupling of α-chloroketones and arylhalides in DMF and in the presence of a Al- or Zn-sacrificial anode and a catalytic amount of a nickel complex.
- Durandetti,Sibille,Nedelec,Perichon
-
p. 145 - 151
(2007/10/02)
-
- Metallic Nickel-Mediated Synthesis of Ketones by the Reaction of Benzylic, Allylic, Vinylic, and Pentafluorophenyl Halides with Acid Halides
-
Metallic nickel was investigated as a convenient coupling reagent for the synthesis of ketones by the reaction of benzylic, allylic, vinylic, and pentafluorophenyl halides with acid halides at 85 deg C in glyme.A variety of benzylic ketones with functional groups including halogen, cyano, methoxycarbonyl, and hydroxycarbonyl groups were prepared in good yields by this method.The reaction was demonstrated to proceed via organonickel halide intermediates formed by the smooth oxidative addition of benzylic and acyl halides to metallic nickel, which were trapped with electron-deficient olefins. (?-Allyl)nickel halides, prepared in situ at 85 deg C from allylic halides and the nickel, also worked for the preparation of ketones.Vinylic and pentafluorophenyl halides but not alkyl halides reacted with acid halides to give the corresponding ketones in moderate yields.
- Inaba, Shin-ichi,Rieke, Reuben D.
-
p. 1373 - 1381
(2007/10/02)
-