73737-55-0Relevant academic research and scientific papers
Transition-Metal-Free Redox-Neutral One-Pot C3-Alkenylation of Indoles Using Aldehydes
Sahu, Samrat,Banerjee, Ankush,Maji, Modhu Sudan
supporting information, p. 464 - 467 (2017/02/10)
The synthesis of sensitive β-alkyl 3-vinylindoles having diverse functional groups with good selectivity remains a challenging task. Keeping the synthetic utility of 3-alkenylindoles in mind, we explored a unique approach to synthesize them from unprotected indoles in a domino fashion. A transition-metal-free C3-alkenylation of indole is reported by using sequential Br?nsted acid/base catalysis. Several β-substituted 3-alkenylindoles and conjugated 1,3-dienes are synthesized by direct coupling of indole and readily available aliphatic aldehydes. Excellent scalability and recycling of benzenesulfinic acid for successive alkenylation reactions up to five times make this method economically viable.
N-heterocyclic carbene catalyzed enantioselective α-fluorination of aliphatic aldehydes and α-chloro aldehydes: Synthesis of α-fluoro esters, amides, and thioesters
Dong, Xiuqin,Yang, Wen,Hu, Weimin,Sun, Jianwei
supporting information, p. 660 - 663 (2015/03/04)
The asymmetric fluorination of azolium enolates that are generated from readily available simple aliphatic aldehydes or α-chloro aldehydes and N-heterocyclic carbenes (NHCs) is described. The process significantly expands the synthetic utility of NHC-catalyzed fluorination and provides facile access to a wide range of α-fluoro esters, amides, and thioesters with excellent enantioselectivity. Pyrazole was identified as an excellent acyl transfer reagent for catalytic amide formation.
A convergent general strategy for the functionalized 2-Aryl cycloalkylfused chromans: Intramolecular hetero-diels-alder reactions of ortho-quinone methides
Tummatorn, Jumreang,Ruchirawat, Somsak,Ploypradith, Poonsakdi
supporting information; experimental part, p. 1445 - 1448 (2010/06/17)
(Figure Presented) Five and six: 3, 4-Cyclopentyl- and cyclohexyl-fused 2-arylchromans could be readily prepared from the intramolecular hetero-Diels-Alder reactions of the corresponding ortho-quinone methide (o-QM) precursors tethered to the styrenes under mild reaction conditions. The products were obtained with good to excellent diastereoselectivity (up to > 99:1 dr; see scheme; MOM = methoxymethyl).
Method for conversion of terminal alkenes to aldehydes using ruthenium(IV) porphyrin catalysts
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Page/Page column 2; sheet 4, (2008/06/13)
Aldehydes were obtained in excellent yields from ruthenium-porphyrin-catalyzed oxidation of various terminal alkenes with 2,6-dichloropyridine N-oxide under mild conditions. The aldehydes generated from these ruthenium-catalyzed alkene oxidation reactions can be used in-situ for olefination reactions with ethyl diazoacetate in the presence of PPh3, leading to one-pot diazoacetate olefination starting from alkenes.
Dichlororuthenium(IV) complex of meso-Tetrakis(2,6-dichlorophenyl) porphyrin: Active and robust catalyst for highly selective oxidation of arenes, Unsaturated steroids, and electron-deficient alkenes by using 2,6-dichloropyridine N-oxide
Zhang, Jun-Long,Che, Chi-Ming
, p. 3899 - 3914 (2007/10/03)
[RuIV(2,6-Cl2tpp)Cl2], prepared in 90% yield from the reaction of [RuVI(2,6-Cl2tpp)O2] with Me3SiCl and structurally characterized by X-ray crystallography, is markedly superior to [RuIv(tmp)Cl2], [RuIV(ttp)Cl2], and [RuII(por)(CO)] (por = 2,6-Cl2tpp, F20-tpp, F28-tpp) as a catalyst for alkene epoxidation with 2,6-Cl2pyNO (2,6Cl2tpp = meso-tetrakis(2,6-dichlorophenyl)porphyrinato dianion; tmp = meso-tetramesitylporphyrinato dianion; ttp = meso-tetrakis(p-tolyl)porphyrinato dianion; F20-tpp = meso-tetrakis(pentafluorophenyl)porphyrinato dianion; F28-tpp = 2,3,7,8,12,13,17,18-octafluoro-5,10,15,20- tetrakis(pentafluorophenyl)-porphyrinato dianion). The "[Ru IV(2,6-Cl2tpp)Cl2] + 2,6-Cl 2pyNO" protocol oxidized, under acid-free conditions, a wide variety of hydrocarbons including 1) cycloalkenes, conjugated enynes, electron-deficient alkenes (to afford epoxides), 2) arenes (to afford quinones), and 3) Δ5-unsaturated steroids, Δ4-3- ketosteroids, and estratetraene derivatives (to afford epoxide/ketone derivatives of steroids) in up to 99% product yield within several hours with up to 100% substrate conversion and excellent regio- or diastereoselectivity. Catalyst [RuIv(2,6-Cl2tpp)Cl2] is remarkably active and robust toward the above oxidation reactions, and turnover numbers of up to 6.4 × 103, 2.0 × 104, and 1.6 × 104 were obtained for the oxidation of α,β-unsaturated ketones, arenes, and Δ5-unsaturated steroids, respectively.
A practical and mild method for the highly selective conversion of terminal alkenes into aldehydes through epoxidation-isomerization with ruthenium(IV)-porphyrin catalysts
Chen, Jian,Che, Chi-Ming
, p. 4950 - 4954 (2007/10/03)
Aldehydes in excellent yields were obtained from the ruthenium-porphyrin- catalyzed oxidation of various terminal alkenes with 2,6-dichloropyridine N-oxide under mild conditions. The aldehydes generated from these ruthenium-catalyzed alkene oxidations can be used in situ for olefination reactions with ethyl diazoacetate in the presence of PPh3 in a one-pot diazoacetate olefination starting from alkenes (see example).
A stereoselective route to trans-2,5-disubstituted tetrahydrofurans
Kang,Hwang,Kim,Lim
, p. 5917 - 5920 (2007/10/02)
An efficient stereocontrolled route to trans-2,5-disubstituted tetrahydrofurans from trans-4-phenyl-3-buten-1-ol derivatives has been developed by using phenylselenyl chloride with zinc bromide in DME at -55°C.
DISSYMETRATION DE LA MOLECULE DU GLYOXAL 1-SYNTHESE ET REACTIVITE DE L'ACETOXY-1 TRIETHOXY-1,2,2 ETHANE
Stambouli, A.,Chastrette, F.,Amouroux, R.,Chastrette, M.,Mattioda, G.,Blanc, A.
, p. 4149 - 4152 (2007/10/02)
Acetoxy-1 triethoxy-1,2,2 ethane, a dissymetric derivative of glyoxal, is prepared and reacted with various bases and nucleophiles, as amines, cyanotrimethylsilane, organometallic and WITTIG reagents.Various acetals are obtained, leading to α-fonctionalized aldehydes.
INTRAMOLECULAR N-ALKENYLNITRONE-ADDITIONS. REGIO- AND STEREOCHEMISTRY
Oppolzer, W.,Siles, S.,Snowden, R. L.,Bakker, B. H.,Petrzilka, M.
, p. 3497 - 3509 (2007/10/02)
Efficient intramolecular cycloadditions of N-3-alkenyl- and N-4-alkenylnitrones proceed with opposite regioselection which is modified by dipolarophile-substituent effects.Polycyclic isoxazolidines are obtained in a highly stereocontrolled fashion, consistent with an endo-addition of the Z-nitrones.
