611-91-6Relevant articles and documents
Do C-H...O and C-H...π interactions help to stabilize a non-centrosymmetric structure for racemic 2,3-dibromo-1,3-diphenyl-propan-1-one?
Harrison, William T. A.,Yathirajan,Sarojini,Narayana,Anilkumar
, p. o728-o730 (2005)
The racemic title compound, C15H12Br2O, crystallizes in a non-centrosymmetric structure and displays a significant non-linear optical response to red light. The crystal packing is influenced by C-H...O and C-H...π interactions. One of the former bonds has a short H...O separation of 2.27 A.
Catalyst-Free 1,2-Dibromination of Alkenes Using 1,3-Dibromo-5,5-dimethylhydantoin (DBDMH) as a Bromine Source
Wang, Lei,Zhai, Lele,Chen, Jinyan,Gong, Yulin,Wang, Peng,Li, Huilin,She, Xuegong
supporting information, p. 3177 - 3183 (2022/02/23)
A direct 1,2-dibromination method of alkenes is realized using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) as a bromine source. This reaction proceeds under mild reaction conditions without the use of a catalyst and an external oxidant. Various sorts of alkene substrates are transformed into the corresponding 1,2-dibrominated products in good to excellent yields with broad substrate scope and exclusive diastereoselectivity. This method offers a green and practical approach to synthesize vicinal dibromide compounds.
New nicotinic acid-based 3,5-diphenylpyrazoles: design, synthesis and antihyperlipidemic activity with potential NPC1L1 inhibitory activity
Shoman, Mai E.,Aboelez, Moustafa O.,Shaykhon, Montaser Sh. A.,Ahmed, Sanaa A.,Abuo-Rahma, Gamal El-Din A.,Elhady, Omar M.
, p. 673 - 686 (2020/02/25)
Nicotinic acid hydrazide was incorporated into new 4,5-dihydro-5-hydroxy-3,5-diphenylpyrazol-1-yl derivatives. Compounds 6a–h were synthesized, and their antihyperlipidemic activity was evaluated in high cholesterol diet-fed rat model. Compounds 6e, 6f were found to decrease the levels of serum total cholesterol by 14–19% compared to control group. Total triglycerides were also reduced by 24–28% and LDL cholesterol by 16%. As expected from parent niacin, compounds 6e and 6f caused an elevation of HDL cholesterol by 33–41%. Docking study supported the ability of designed compounds to block NPC1L1 active site in a manner similar to that observed with ezetimibe.
Visible light-mediated metal-free double bond deuteration of substituted phenylalkenes
Iakovenko, Roman,Hlavá?, Jan
supporting information, p. 440 - 446 (2021/01/28)
Various bromophenylalkenes were reductively photodebrominated by using 1,3-dimethyl-2-phenyl-1H-benzo-[d]imidazoline (DMBI) and 9,10-dicyanoanthracene. With deuterated DMBI analogs (the most effective was DMBI-d11), satisfactory to excellent isotopic yields were obtained. DMBI-d11 could also be regenerated from the reaction mixtures with a recovery rate of up to 50%. The combination of the photodebromination reaction with conventional methods for bromoalkene synthesis enables sequential monodeuteration of a double bond without the necessity of a metal catalyst. This journal is
Modular access to 1,2-allenyl ketones based on a photoredox-catalysed radical-polar crossover process
Du, Chan,Fang, Jianghua,Fang, Yewen,Lei, Wan,Li, Yan,Liu, Yongjun
supporting information, p. 8502 - 8506 (2021/10/20)
Herein, a new protocol dealing with the preparation of 1,2-allenyl ketones has been successfully developedviathe reactions of enynes with radicals enabled by dual photoredox/copper catalysis. Based on the results of a deuteration experiment and the competition reaction between cyclopropanation and allenation, the mechanism based on a photoredox-neutral-catalysed radical-polar crossover process has been proposed. Synthetic applications of allenes have also been demonstrated.
Dibrominated addition and substitution of alkenes catalyzed by Mn2(CO)10
Chan, Albert S. C.,Jiang, Yi,Meng, Shanshui,Song, Xianheng,Zhang, Hong,Zou, Yong
supporting information, p. 13385 - 13388 (2021/12/17)
A practical method for the dibromination of alkenes without using molecular bromine is consistently appealing in organic synthesis. Herein, we report Mn-catalyzed dibrominated addition and substitution of alkenes only with N-bromosuccinimide, producing a variety of synthetically valuable dibrominated compounds in moderate to high yields. This journal is
Synthesis of α,β-dibromo ketones by photolysis of α-bromo ketones with N-bromosuccinimide: Photoinduced β-bromination of α-bromo ketones
Moon, Da Yoon,An, Sejin,Park, Bong Ser
, (2019/10/28)
Irradiation of α-bromopropiophenones in the presence of NBS results in the formation of α,β-dibromopropiophenones, which can be viewed as β-bromination of α-bromopropiophenones. The reaction is believed to go through a series of reactions; photoinduced C–Br bond cleavage, elimination of HBr to give α,β-unsaturated ketone intermediates, and addition of Br2, which are formed by the reaction between HBr and NBS. From mechanistic studies of the reaction, we have also found a very convenient method for α-debromination of the α,β-dibromopropiophenones which is by simple irradiation of the dibromo ketones in acetone or 2-propanol without the use of any additives. Our results demonstrate that bromine can be added into or eliminated from the alpha, beta, or both positions to the carbonyl group by photochemical methods, which make synthetic options of bromine containing carbonyl compounds versatile.
Dibromination of alkenes with LiBr and H2O2 under mild conditions
Martins, Nayara Silva,Alberto, Eduardo E.
supporting information, p. 161 - 167 (2017/12/28)
Electron-rich and electron-poor alkenes, and alkenes bearing protecting groups can be efficiently and stereoselectively converted to trans-dibromides using LiBr/H2O2 and AcOH as a proton source in 1,4-dioxane. For most substrates addition of 0.1 mol% of PhTeTePh enhances the reaction rate and the yield of the products. Experimental data suggest that the brominating agent prepared in situ is molecular bromine and that LiBr assists the activation of H2O2 allowing bromination to occur using AcOH as a mild proton source in uncatalyzed experiments. Scale-up is feasible: 10.0 mmol of 1-octene was quantitatively converted to 1,2-dibromooctene in one hour of reaction at room temperature.
Solvent free, light induced 1,2-bromine shift reaction of α-bromo ketones
An, Sejin,Moon, Da Yoon,Park, Bong Ser
, p. 6922 - 6928 (2018/10/24)
Photolysis of α-bromopropiophenones in acetonitrile results in formation of β-bromopropiophenones with good product selectivity, which can be coined as 1,2-Br shift reaction. The product selectivity increases when the reaction is done in neat or solid state, where only the 1,2-Br shift product is formed in some cases. The reaction is suggested to proceed by C–Br bond homolysis to give a radical pair, followed by disproportionation and conjugate addition of HBr to the α,β-unsaturated ketone intermediate. When the unsaturated intermediate is stabilized by an extra conjugation, the reaction stops at the stage, in which the unsaturated ketone becomes a major product. The synthetic method described in this research fits in a category of eco-friendly organic synthesis nicely since the reaction does not use volatile organic solvents and any other additives such as acid, base or metal catalysts, etc. Besides, the method fits into perfect atom economy, which does not give any side products. The synthetic method should find much advantage over other alternative methods to obtain β-bromo carbonyl compounds.
A new synthetic strategy towards 2,4,5-trisubstituted 1H-imidazoles and highly substituted pyrrolo[1,2-c]imidazoles by use of α-azidochalcones via Michael addition-cyclization followed by Wittig reaction
Adib, Mehdi,Peytam, Fariba,Rahmanian-Jazi, Mahmoud,Bijanzadeh, Hamid Reza,Amanlou, Massoud
, p. 6696 - 6705 (2017/10/25)
Efficient and facile protocols for the preparation of highly functionalized 1H-imidazoles and 5H-pyrrolo[1,2-c]imidazoles are described. Heating a mixture of an α-azidochalcones and N,N,N′,N′-tetramethyl guanidine under neat conditions gave the corresponding 2,4,5-trisubstituted 1H-imidazole via Michael addition-cyclization in excellent yields. Subsequently, the prepared 1H-imidazoles undergo addition-Wittig reaction with acetylenic esters in presence of triphenylphosphine in dichloromethane to afford 5H-pyrrolo[1,2-c]imidazoles in high yields.
