26905-44-2Relevant academic research and scientific papers
Rhodium-Catalyzed Synthesis of α,β-Unsaturated Ketones through Sequential C-C Coupling and Redox Isomerization
Li, Hong-Shuang,Guo, Guili,Zhang, Rui-Ze,Li, Fei
, p. 5040 - 5043 (2018)
A novel Rh(I)-catalyzed sequential C-C coupling and redox isomerization between allylic alcohols and 1,3-dienes has been accomplished. This versatile protocol provides expeditious access to a broad range of polysubstituted α,β-unsaturated ketones with excellent atom economy and regioselectivity.
Catalytic Asymmetric Allylic Substitution with Copper(I) Homoenolates Generated from Cyclopropanols
Shi, Chang-Yun,Yin, Liang,Zhang, Qi,Zhou, Si-Wei
supporting information, p. 26351 - 26356 (2021/11/09)
By using copper(I) homoenolates as nucleophiles, which are generated through the ring-opening of 1-substituted cyclopropane-1-ols, a catalytic asymmetric allylic substitution with allyl phosphates is achieved in high to excellent yields with high enantioselectivity. Both 1-substituted cyclopropane-1-ols and allylic phosphates enjoy broad substrate scopes. Remarkably, various functional groups, such as ether, ester, tosylate, imide, alcohol, nitro, and carbamate are well tolerated. Moreover, the present method is nicely extended to the asymmetric construction of quaternary carbon centers. Some control experiments argue against a radical-based reaction mechanism and a catalytic cycle based on a two-electron process is proposed. Finally, the synthetic utilities of the product are showcased by means of the transformations of the terminal olefin group and the ketone group.
Highly Regio- A nd Enantioselective Hydrogenation of Conjugated α-Substituted Dienoic Acids
Liu, Xian,Liu, Song,Wang, Quanjun,Zhou, Gang,Yao, Lin,Ouyang, Qin,Jiang, Ru,Lan, Yu,Chen, Weiping
, p. 3149 - 3154 (2020/04/09)
Highly regio- A nd enantioselective hydrogenation of conjugated α-substituted dienoic acids was realized for the first time using Trifer-Rh complex, providing a straightforward method for the synthesis of chiral α-substituted ?,?′-unsaturated acids. DFT calculations revealed N+H-O hydrogen bonding interaction is formed to stabilize the transition state and the coordination of 4,5-double bond to Rh(III) center would facilitate the reductive elimination process. This hydrogenation provided a gram-scale synthesis of the precursor of sacubitril.
Dual-targeting Rutaecarpine-NO donor hybrids as novel anti-hypertensive agents by promoting release of CGRP
Ma, Jinjin,Chen, Lan,Fan, Jinbao,Cao, Wei,Zeng, Guangyao,Wang, Yajing,Li, Yuanjian,Zhou, Yingjun,Deng, Xu
, p. 146 - 153 (2019/02/27)
CGRP, known as the most potent vasodilator substance, plays an important role in hypertension initiation and development. TRPV1 and TRPA1 are critical in promoting the synthesis and release of CGRP, thereby regulating the cardiovascular tone. Rutaecarpine exhibits potent vasodilator and hypertensive effects by stimulating CGRP synthesis and release via activation of TRPV1. And NO has been shown to react with H2S in vivo to form HNO, thereby activating HNO-TRPA1-CGRP pathway. Inspired by combination therapy, 11 rutaecarpine-furoxan hybrids were designed, synthesized and evaluated. The results demonstrated that most hybrids exerted comparable or improved vasodilator activities. Among which, 13a is the most potent both ex vivo (EC50 = 13.1 nM) and in vivo. Mechanistic studies revealed that the vasodilator and anti-hypertensive effects of the hybrids might involve the promotion of CGRP release via dual activation of TRPV1 and TRPA1. This work suggests that dual-targeted hybrids might be an effective and promising approach to discover and develop novel anti-hypertensive drugs.
Stereodivergent allylic substitutions with aryl acetic acid esters by synergistic iridium and lewis base catalysis
Jiang, Xingyu,Beiger, Jason J.,Hartwig, John F.
supporting information, p. 87 - 90 (2017/05/16)
The preparation of all possible stereoisomers of a given chiral molecule bearing multiple stereocenters by a simple and unified method is a significant challenge in asymmetric catalysis. We report stereodivergent allylic substitutions with aryl acetic acid esters catalyzed synergistically by a metallacyclic iridium complex and benzotetramisole. Through permutations of the enantiomers of the two chiral catalysts, all four stereoisomers of the products bearing two adjacent stereocenters are accessible with high diastereoselectivity and enantioselectivity. The resulting chiral activated ester products can be converted readily to enantioenriched amides, unactivated esters, and carboxylic acids in a onepot manner.
Iridium-Catalyzed Enantioselective Allylic Substitution of Aliphatic Esters with Silyl Ketene Acetals as the Ester Enolates
Jiang, Xingyu,Hartwig, John F.
supporting information, p. 8887 - 8891 (2017/07/17)
Enantioselective allylic substitution with enolates derived from aliphatic esters under mild conditions remains challenging. Herein we report iridium-catalyzed enantioselective allylation reactions of silyl ketene acetals, the silicon enolates of esters, to form products containing a quaternary carbon atom at the nucleophile moiety and a tertiary carbon atom at the electrophile moiety. Under relatively neutral conditions, the allylated aliphatic esters were obtained with excellent regioselectivity and enantioselectivity. These products were readily converted into primary alcohols, carboxylic acids, amides, isocyanates, and carbamates, as well as tetrahydrofuran and γ-butyrolactone derivatives, without erosion of enantiomeric purity.
Stereoselective and Site-Specific Allylic Alkylation of Amino Acids and Small Peptides via a Pd/Cu Dual Catalysis
Huo, Xiaohong,He, Rui,Fu, Jingke,Zhang, Jiacheng,Yang, Guoqiang,Zhang, Wanbin
supporting information, p. 9819 - 9822 (2017/08/02)
We report a stereoselective and site-specific allylic alkylation of Schiff base activated amino acids and small peptides via a Pd/Cu dual catalysis. A range of noncoded α,α-dialkyl α-amino acids were easily synthesized in high yields and with excellent enantioselectivities (up to >99% ee). Furthermore, a direct and highly stereoselective synthesis of small peptides with enantiopure α-alkyl or α,α-dialkyl α-amino acids residues incorporated at specific sites was accomplished using this dual catalyst system.
Discovery of Potent Benzofuran-Derived Diapophytoene Desaturase (CrtN) Inhibitors with Enhanced Oral Bioavailability for the Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) Infections
Wang, Youxin,Chen, Feifei,Di, Hongxia,Xu, Yong,Xiao, Qiang,Wang, Xuehai,Wei, Hanwen,Lu, Yanli,Zhang, Lingling,Zhu, Jin,Sheng, Chunquan,Lan, Lefu,Li, Jian
, p. 3215 - 3230 (2016/05/19)
Blocking the staphyloxanthin biosynthesis process has emerged as a new promising antivirulence strategy. Previously, we first revealed that CrtN is a druggable target against infections caused by pigmented Staphylococcus aureus (S. aureus) and that naftifine was an effective CrtN inhibitor. Here, we identify a new type of benzofuran-derived CrtN inhibitor with submicromolar IC50 values that is based on the naftifine scaffold. The most potent analog, 5m, inhibits the pigment production of S. aureus Newman and three MRSA strains, with IC50 values of 0.38-5.45 nM, without any impact on the survival of four strains (up to 200 μM). Notably, compound 5m (1 μM) could significantly sensitize four strains to immune clearance and could effectively attenuate the virulence of three strains in vivo. Moreover, 5m was determined to be a weak antifungal reagent (MIC > 16 μg/mL). Combined with good oral bioavailability (F = 42.2%) and excellent safety profiles, these data demonstrate that 5m may be a good candidate for the treatment of MRSA infections.
Ligand-Controlled Regiodivergence in the Copper-Catalyzed [2,3]- and [1,2]-Rearrangements of Iodonium Ylides
Xu, Bin,Tambar, Uttam K.
supporting information, p. 12073 - 12076 (2016/09/28)
Despite the importance of allylic ylide rearrangements for the synthesis of complex molecules, the catalyst control of [2,3]- and [1,2]-rearrangements remains an unsolved problem. We developed the first regiodivergent [2,3]- and [1,2]-rearrangements of iodonium ylides that are controlled by copper catalysts bearing different ligands. In the presence of a 2,2′-dipyridyl ligand, diazoesters and allylic iodides react via a [2,3]-rearrangement pathway. Alternatively, a phosphine ligand favors the formation of the [1,2]-rearrangement product. A series of α-iodoesters containing a broad range of functional groups were obtained in high yields, regioselectivities, and diastereoselectivities. Deuterium-labeling studies suggest distinct mechanisms for the regioselective rearrangements.
Catalytic asymmetric bromochlorination of aromatic allylic alcohols promoted by multifunctional Schiff base ligands
Huang, Wei-Sheng,Chen, Li,Zheng, Zhan-Jiang,Yang, Ke-Fang,Xu, Zheng,Cui, Yu-Ming,Xu, Li-Wen
, p. 7927 - 7932 (2016/08/30)
It was found that the tridentate O,N,O-type Schiff base ligand bearing suitable substituents was a highly effective promoter in the catalytic asymmetric bromochlorination reaction, in which the corresponding aromatic bromochloroalcohols with vicinal halogen-bearing stereocenters were formed with perfect regioselectivity, with moderate to excellent enantioselectivities (up to 93% ee), and with good yields and chemoselectivities.
