25308-75-2Relevant academic research and scientific papers
Visible-Light Photoredox Catalyzed Dehydrogenative Synthesis of Allylic Carboxylates from Styrenes
Bandini, Marco,Battaglioli, Simone,Liu, Yang,Lombardi, Lorenzo,Menichetti, Arianna,Montalti, Marco,Valenti, Giovanni
, p. 4441 - 4446 (2021/06/28)
The visible-light photoredox/[Co(III)] cocatalyzed dehydrogenative functionalization of cyclic and acyclic styryl derivatives with carboxylic acids is documented. The methodology enables the chemo- and regioselective allylic functionalization of styryl compounds, leading to allylic carboxylates (32 examples) under stoichiometric acceptorless conditions. Intermolecular as well as intramolecular variants are documented in high yields (up to 82%). A mechanistic rationale is also proposed on the basis of a combined experimental and spectroscopic investigation.
Iodobenzene-catalyzed oxidative cleavage of olefins to carbonyl compounds
Du, Lele,Wang, Zechao,Wu, Junliang
, (2020/07/20)
A metal-free approach for the oxidative cleavage of carbon–carbon double bonds of olefins to carbonyl compounds was established by using oxidant m-CPBA and non-metallic organocatalyst PhI in toluene/H2O. A broad scope of aromatic olefins was used. All the reactions proceeded smoothly at 35 °C in short reaction time to furnish the respective mono- and double carbonyl compounds selectively in moderate to good yields.
Bimolecular vinylation of arenes by vinyl cations
Bour, Christophe,Gandon, Vincent,Li, Zhilong
supporting information, p. 6507 - 6510 (2020/07/02)
Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
Catalytic Redox Chain Ring Opening of Lactones with Quinones to Synthesize Quinone-Containing Carboxylic Acids
Xu, Xiao-Long,Li, Zhi
supporting information, p. 5078 - 5081 (2019/09/03)
Catalytic ring opening of five- to eight-membered lactones with quinones is achieved through a redox chain mechanism. With low loading of a simple metal triflate Lewis acid catalyst and a chain initiator, C-H bonds of many quinones were efficiently functionalized with carboxylic acid-containing side chains. This method also features 100% atom economy and wide substrate scope. A novel route to the anti-asthma drug Seratrodast was developed. Mechanism study suggests that the redox chain reaction likely undergoes a carbocation intermediate.
Triphosgene and DMAP as Mild Reagents for Chemoselective Dehydration of Tertiary Alcohols
Ganiu, Moshood O.,Cleveland, Alexander H.,Paul, Jarrod L.,Kartika, Rendy
supporting information, p. 5611 - 5615 (2019/08/01)
The utility of triphosgene and DMAP as mild reagents for chemoselective dehydration of tertiary alcohols is reported. Performed in dichloromethane at room temperature, this reaction is readily tolerated by a broad scope of substrates, yielding alkenes preferentially with the (E)-geometry. While formation of the Hofmann products is generally favored, a dramatic change in alkene selectivity toward the Zaitzev products is observed when the reaction is carried out in dichloroethane at reflux.
Efficient functionalization of olefins by arylsilanes catalyzed by palladium anionic complexes
Silarska,Majchrzak,Marciniec,Trzeciak
, p. 458 - 464 (2016/12/16)
The coupling of organosilanes and different olefins was performed efficiently in the presence of anionic complexes, [CA]2[PdX4] and [CA]2[Pd2X6], where CA?=?imidazolium or pyridinium cation. The reaction proceeds according to a Pd(II)-mediated pathway, and Cu(OAc)2 acts as the re-oxidant of Pd(0) formed during the catalytic process. High product yields were obtained for differently substituted olefins at 80?°C in 4?h. Styrylsilanes reacted in the same conditions giving unsymmetrical 1,3-dienes.
Nickel-Catalyzed Direct Synthesis of Aryl Olefins from Ketones and Organoboron Reagents under Neutral Conditions
Lei, Chuanhu,Yip, Yong Jie,Zhou, Jianrong Steve
supporting information, p. 6086 - 6089 (2017/05/08)
Nickel-catalyzed addition of arylboron reagents to ketones results in aryl olefins directly. The neutral condition allows acidic protons of alcohols, phenols, and malonates to be present, and fragile structures are also tolerated.
Oxygen-promoted coupling of arylboronic acids with olefins catalyzed by [CA]2[PdX4] complexes without a base
Silarska,Trzeciak
, p. 1 - 11 (2015/07/28)
Abstract An efficient method was developed for the oxidative Heck reaction between arylboronic acids and olefins catalyzed by anionic palladium complexes of the type [CA]x[PdCl4] (x = 1,2) and [CA]2[Pd2Cl6] (CA = imidazolium or pyridinium cation). Molecular oxygen was employed as an environmentally benign oxidant to regenerate Pd(II) species during the reaction. The elaborated protocol could be applied to the coupling of different arylboronic acids with both electron-rich and electron-poor olefins. The catalyst system was further employed for the one-pot oxidative Heck reaction followed by the Heck coupling to build conjugated compounds in good yield. Mass spectrometry (ESI-MS) and UV-vis spectroscopy was used to identify palladium-containing complexes in the reactions. A plausible reaction mechanism of the oxidative Heck reaction was proposed.
Auto de-bromine-coupling reactions of 1-aryl-7-bromocycloheptenes
Lee, Gon-Ann,Lee, Hsin-Yi,Wang, Wen-Chieh,Cherng, Chih-Hwa
, p. 2956 - 2961 (2014/04/17)
Auto de-bromine-coupling reactions of 1-aryl-7-bromocycloheptenes to a new series of [7-6-6] tricyclic system were described. A variety of substituents at the para-position of the phenyl were amenable to this transformation, including electron-donating groups and halides. The presence of electron-donating groups resulted in a more efficient reaction, with higher yields than the case of halides.
Sulfur mediated allylic C-H alkylation of tri- and disubstituted olefins
Hu, Gang,Xu, Jiaxi,Li, Pingfan
supporting information, p. 6036 - 6039 (2015/01/08)
A novel transition-metal-free, sulfur mediated allylic C-H alkylation reaction through a one-pot procedure involving an ene-like step between simple olefins and activated sulfoxides to generate allylic sulfonium intermediates, and a subsequent [2,3]-sigmatropic rearrangement step under basic conditions to give allylic C-H alkylation products, has been developed. This method is applicable to tri- and disubstituted olefin substrates in both inter- and intramolecular fashions.
