33458-08-1Relevant academic research and scientific papers
Photoredox-catalyzed synthesis of N-unsubstituted enaminosulfones from vinyl azides and sulfinates
Mulina, Olga M.,Ilovaisky, Alexey I.,Opatz, Till,Terent'ev, Alexander O.
supporting information, (2021/01/11)
A metal-free visible light photoredox-catalyzed synthesis of N-unsubstituted enaminosulfones from vinyl azides and sodium sulfinates in moderate to high yields is described. The reaction proceeds in ethanol and uses eosin Y as a readily available photocatalyst in combination with nitrobenzene as an electron shuttle. Taking into account the number of steps involved (generation of the sulfonyl radical, its addition to the double bond, elimination of molecular nitrogen with formation of an iminyl radical, followed by its reduction and protonation) as well as the number of redox-active reaction partners involved, the selectivity of the process is quite impressive.
Electrosynthesis of N-unsubstituted enaminosulfones from vinyl azides and sodium sulfinates mediated by NH4I
Mulina, Olga M.,Doronin, Mikhail M.,Terent'ev, Alexander O.
supporting information, (2021/10/16)
A wide range of N-unsubstituted enaminosulfones were obtained via electrochemical sulfonylation of vinyl azides with sulfonyl radicals generated from sodium sulfinates. The discovery of N-unsubstituted enaminosulfones synthesis is based on a unique ability of the azido group to eliminate the N2 molecule. The process is performed under constant current conditions in an experimentally convenient undivided electrochemical cell equipped with a graphite anode and a stainless steel cathode applying NH4I both as the redox catalyst and the supporting electrolyte.
A General Method for the Dibromination of Vicinal sp3C-H Bonds Exploiting Weak Solvent-Substrate Noncovalent Interactions
Qi, Zaojuan,Li, Weihe,Niu, Yanning,Benassi, Enrico,Qian, Bo
supporting information, p. 2399 - 2404 (2021/03/03)
A general procedure of 1,2-dibromination of vicinal sp3 C-H bonds of arylethanes using N-bromosuccinimide as the bromide reagent without an external initiator has been established. The modulation of the strength of the intermolecular noncovalent interactions between the solvent and arylethane ethanes, quantitatively evaluated via quantum chemical calculations, allows us to circumvent the fact that arylethane ethane cannot be dibrominated through traditional methods. The mechanism was explored by both experiments and quantum chemical calculations, revealing a radical chain with HAA process.
The intramolecular reaction of acetophenoneN-tosylhydrazone and vinyl: Br?nsted acid-promoted cationic cyclization toward polysubstituted indenes
Wang, Zhixin,Li, Yang,Chen, Fan,Qian, Peng-Cheng,Cheng, Jiang
supporting information, p. 1810 - 1813 (2021/02/27)
In the presence of TsNHNH2, a Br?nsted acid-promoted intramolecular cyclization ofo-(1-arylvinyl) acetophenone derivatives was developed, leading to polysubstituted indenes with complexity and diversity in moderate to excellent yields. In sharp contrast with either the radical or carbene involved cyclization of aldehydicN-tosylhydrazone with vinyl, a cationic cyclization pathway was involved, whereN-tosylhydrazone served as an electrophile and alkylation reagent during this transformation.
Electrochemical Synthesis of O-Phthalimide Oximes from α-Azido Styrenes via Radical Sequence: Generation, Addition and Recombination of Imide-N-Oxyl and Iminyl Radicals with C?O/N?O Bonds Formation
Paveliev, Stanislav A.,Churakov, Artem I.,Alimkhanova, Liliya S.,Segida, Oleg O.,Nikishin, Gennady I.,Terent'ev, Alexander O.
supporting information, p. 3864 - 3871 (2020/07/30)
Electrochemically induced radical-initiated reaction of vinyl azides with N-hydroxyphthalimide resulting O-phthalimide oximes with challenging for organic chemistry N?O-N fragment has been discovered. The developed approach introduces in synthesis electrochemically generated O-centered imide-N-oxyl radicals as the coupling components. Sequential formation of C?O and N?O bonds was achieved via generation and selective addition of imide-N-oxyl radicals, followed by recombination with iminyl radicals. A wide range of O-phthalimide oximes was obtained with the yields up to 84percent. (Figure presented.).
Asymmetric Nazarov Cyclizations of Unactivated Dienones by Hydrogen-Bond-Donor/Lewis Acid Co–Catalyzed, Enantioselective Proton-Transfer
Metternich, Jan B.,Reiterer, Martin,Jacobsen, Eric N.
supporting information, p. 4092 - 4097 (2020/09/01)
We report an enantioselective Nazarov cyclization catalyzed by chiral hydrogen-bond-donors in concert with silyl Lewis acids. The developed transformation provides access to tri-substituted cyclopentenones in high levels of enantioselectivity (up to 95% e.e.) from a variety of simple unactivated dienones. Kinetic and mechanistic studies are consistent with a reversible 4π-electrocyclization C?C bond-forming step followed by rate- and enantio-determining proton-transfer as the mode of catalysis. (Figure presented.).
Preparation method of 1-aryl-1,2-dibromoethane
-
Paragraph 0018-0019, (2020/03/16)
The invention relates to a preparation method of 1-aryl-1,2-dibromoethane. The preparation method of 1-aryl-1,2-dibromoethane includes the steps: under a nitrogen atmosphere, a solvent, an aryl alkaneand N-bromosuccinimide are added in to a reaction tube in sequence, a dibromination reaction is conducted at 80-120 DEG C for 12-48 hours, then, the dibromination reaction is finished, the solvent isremoved through evaporation, and through column chromatography separation, 1-aryl-1,2-dibromoethane compounds are obtained. According to the preparation method of 1-aryl-1,2-dibromoethane, a synthesis technology is simple, reaction conditions are mild, the yield of 1-aryl-1,2-dibromoethane is high, and thus the preparation method of 1-aryl-1,2-dibromoethane is easy to industrialize.
A Cascade Suzuki-Miyaura/Diels-Alder Protocol: Exploring the Bifunctional Utility of Vinyl Bpin
Cain, David L.,McLaughlin, Calum,Molloy, John J.,Carpenter-Warren, Cameron,Anderson, Niall A.,Watson, Allan J. B.
supporting information, p. 787 - 791 (2019/04/25)
Cascade reactions are an important strategy in reaction design, allowing streamlining of chemical synthesis. Here we report a cascade Suzuki-Miyaura/Diels-Alder reaction, employing vinyl Bpin as a bifunctional reagent in two distinct roles: as an organoboron nucleo phile for cross-coupling and as a Diels-Alder dienophile. Merging these two reactions enables a rapid and operationally simple synthesis of functionalized carbocycles in good yield. The effect of the organoboron subtype on Diels-Alder regioselectivity was investigated and postsynthetic modifications were carried out on a model substrate. The potential for a complementary Heck/Diels-Alder process was also assessed.
Atom-economical brominations with tribromide complexes in the presence of oxidants
Yubata, Kotaro,Matsubara, Hiroshi
supporting information, p. 1001 - 1004 (2019/03/13)
Bromination is an important transformation in organic synthesis, and novel efficient bromination techniques are still required. Herein, we demonstrate atom-economical brominations using (DMI)2HBr3, a novel tribromide complex, with oxidants such as DMSO and Oxone. Using this system, olefinic and aromatic brominations, as well as selective α-monobrominations of ketones proceeded well to afford the desired bromides in good yields. Importantly, in these reactions all of the bromine atoms in this complex are used to brominate.
Preparation of a novel bromine complex and its application in organic synthesis
Nishio, Yuya,Yubata, Kotaro,Wakai, Yutaro,Notsu, Kotaro,Yamamoto, Katsumi,Fujiwara, Hideki,Matsubara, Hiroshi
, p. 1398 - 1405 (2019/02/07)
Although molecular bromine (Br2) is a useful brominating reagent, it is not easy to handle. Herein, we describe the preparation of a novel air-stable bromine complex prepared from 1,3-dimethyl-2-imidazolidinone (DMI) and Br2, which was identified to be (DMI)2HBr3 by spectral and X-ray techniques. This complex was then used to brominate olefins, carbonyl compounds, and aromatics, as well as in the Hofmann rearrangement. Yields of reaction products using this complex were almost the same or superior to those using other bromine alternatives.
