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1.
Wenxuan Xue Yijie Jiang Prof. Dr. Hongcheng Lu Prof. Dr. Bo You Dr. Xu Wang Prof. Dr. Conghui Tang 《Angewandte Chemie (International ed. in English)》2023,62(52):e202314364
The utilization of a single-atom catalyst to break C−C bonds merges the merits of homogeneous and heterogeneous catalysis and presents an intriguing pathway for obtaining high-value-added products. Herein, a mild, selective, and sustainable oxidative cleavage of alkene to form oxime ether or nitrile was achieved by using atomically dispersed cobalt catalyst and hydroxylamine. Diversified substrate patterns, including symmetrical and unsymmetrical alkenes, di- and tri-substituted alkenes, and late-stage functionalization of complex alkenes were demonstrated. The reaction was successfully scaled up and demonstrated good performance in recycling experiments. The hot filtration test, catalyst poisoning and radical scavenger experiment, time kinetics, and studies on the reaction intermediate collectively pointed to a radical mechanism with cobalt/acid/O2 promoted C−C bond cleavage as the key step. 相似文献
2.
Yuhang Zhu Yilei Liao Shuqi Jin Liyuan Ding Prof. Dr. Guofu Zhong Prof. Dr. Jian Zhang 《Chemical record (New York, N.Y.)》2023,23(5):e202300012
Aryl alkenes represents one of the most widely occurring structural motif in countless drugs and natural products, and direct C−H functionalization of aryl alkenes provides atom- step efficient access toward valuable analogues. Among them, group-directed selective olefinic α- and β-C−H functionalization, bearing a directing group on the aromatic ring, has attracted remarkable attentions, including alkynylation, alkenylation, amino-carbonylation, cyanation, domino cyclization and so on. These transformations proceed by endo- and exo−C−H cyclometallation and provide aryl alkene derivatives in excellent site- stereo-selectivity. Enantio-selective α- and β- olefinic C−H functionalization were also covered to synthesis axially chiral styrenes. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(4):1140-1144
Direct cross‐coupling between alkenes/R‐H or alkenes/RXH is a dream reaction, especially without external oxidants. Inputting energy by photocatalysis and employing a cobalt catalyst as a two‐electron acceptor, a direct C−H/X−H cross‐coupling with H2 evolution has been achieved for C−O and C−N bond formation. A new radical alkenylation using alkene as the redox compound is presented. A wide range of aliphatic alcohols—even long chain alcohols—are tolerated well in this system, providing a new route to multi‐substituted enol ether derivatives using simple alkenes. Additionally, this protocol can also be used for N ‐vinylazole synthesis. Mechanistic insights reveal that the cobalt catalyst oxidizes the photocatalyst to revive the photocatalytic cycle. 相似文献
4.
Shuyao Zhang Chenhuan Wang Xiaohan Ye Prof. Xiaodong Shi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20650-20654
The gold-catalyzed intermolecular oxyarylation of alkenes is reported. This work employed the oxidative addition of aryl iodides to Me−DalphosAu+ for the formation of a AuIII−Ar intermediate. The better binding ability of alkenes over O nucleophiles ensured the success of intermolecular oxyarylation, giving desired products with a broad substrate scope and high efficiency (>50 examples with up to 95 % yield). One-pot converting of methoxy groups into other nucleophiles allowed achieving alkene difunctionalization with the construction of C−N, C−S, and C−C bonds under mild conditions. 相似文献
5.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(25):7306-7310
Direct alkylation of a methyl group, on di‐ and trisubstituted ureas, with terminal alkenes by C(sp3)−H bond activation proceeded in the presence of a hydroxoiridium/bisphosphine catalyst to give high yields of the corresponding addition products. The hydroxoiridium/bisphosphine complex generates an amidoiridium intermediate by reaction with ureas having an N−H bond. 相似文献
6.
Daisuke Yamauchi Dr. Takahiro Nishimura Prof. Dr. Hideki Yorimitsu 《Angewandte Chemie (International ed. in English)》2017,56(25):7200-7204
Direct alkylation of a methyl group, on di- and trisubstituted ureas, with terminal alkenes by C(sp3)−H bond activation proceeded in the presence of a hydroxoiridium/bisphosphine catalyst to give high yields of the corresponding addition products. The hydroxoiridium/bisphosphine complex generates an amidoiridium intermediate by reaction with ureas having an N−H bond. 相似文献
7.
Dr. Bo Yang Dr. Wu Yang Yonghong Guo Lijun You Prof. Dr. Chuan He 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22401-22406
A rhodium(I)-catalyzed enantioselective silylation of aliphatic C−H bonds for the synthesis of silicon-stereogenic dihydrobenzosiloles is demonstrated. This reaction involves a highly enantioselective intramolecular C(sp3)−H silylation of dihydrosilanes, followed by a stereospecific intermolecular alkene hydrosilylation leading to the asymmetrically tetrasubstituted silanes. A wide range of dihydrosilanes and alkenes displaying various functional groups are compatible with this process, giving access to a variety of highly functionalized silicon-stereogenic dihydrobenzosiloles in good to excellent yields and enantioselectivities. 相似文献
8.
Dr. Jayachandran Jayakumar Guganchandar Vedarethinam Huan-Chang Hsiao Shang-You Sun Prof. Dr. Shih-Ching Chuang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(2):699-704
Quaternary ammonium salts were synthesized in moderate to good yields through double oxidative C−H bond activation on azobenzenes. The mechanism of the highly regioselective reaction of 2-azobiaryls with alkenes to give orange-red-fluorescent cinnolino[2,3-f]phenanthridin-9-ium salts and 15H-cinnolino[2,3-f]phenanthridin-9-ium-10-ide is proposed to involve ortho C−H olefination of the 2-azobiaryl compound with the alkene, intramolecular aza-Michael addition, concerted metalation–deprotonation (CMD), reductive elimination, and oxidation. 相似文献
9.
Dr. Debdeep Mandal Shubhadeep Chandra Dr. Nicolás I. Neuman Alok Mahata Arighna Sarkar Dr. Abhinanda Kundu Dr. Srinivas Anga Hemant Rawat Prof. Dr. Carola Schulzke Dr. Kaustubh R. Mote Prof. Dr. Biprajit Sarkar Prof. Vadapalli Chandrasekhar Dr. Anukul Jana 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(27):5951-5955
A N-heterocyclic olefin (NHO), a terminal alkene selectively activates aromatic C−F bonds without the need of any additional catalyst. As a result, a straightforward methodology was developed for the formation of different fluoroaryl-substituted alkenes in which the central carbon–carbon double bond is in a twisted geometry. 相似文献
10.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(32):9645-9649
A catalytic intermolecular allylic C−H trifluoromethoxylation reaction of alkenes has been developed based on the use of a palladium catalyst, CsOCF3 as the trifluoromethoxide source, and benzoquinone as the oxidant. This reaction provides an efficient route for directly accessing allylic trifluoromethoxy derivatives with excellent regioselectivities from terminal alkenes via an allylic C−H bond activation process. 相似文献
11.
Dr. Yong Xia Kalipada Jana Prof. Dr. Armido Studer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16621-16625
Desaturation of inert aliphatic C−H bonds in alkanes to form the corresponding alkenes is challenging. In this communication, a new and practical strategy for remote site-selective desaturation of amides via radical chemistry is reported. The readily installed N-allylsulfonylamide moiety serves as an N radical precursor. Intramolecular 1,5-hydrogen atom transfer from an inert C−H bond to the N-radical generates a translocated C-radical which is subsequently oxidized and deprotonated to give the corresponding alkene. The commercially available methanesulfonyl chloride is used as reagent and a Cu/Ag-couple as oxidant. The remote desaturation is realized on different types of unactivated sp3-C−H bonds. The potential synthetic utility of this method is further demonstrated by the dehydrogenation of natural product derivatives and drugs. 相似文献
12.
Pu‐Sheng Wang Hua‐Chen Lin Yu‐Jia Zhai Zhi‐Yong Han Liu‐Zhu Gong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(45):12414-12417
The first enantioselective α‐allylation of aldehydes with terminal alkenes has been realized by combining asymmetric counteranion catalysis and palladium‐catalyzed allylic C H activation. This method can tolerate a wide scope of α‐branched aromatic aldehydes and terminal alkenes, thus affording allylation products in high yields and with good to excellent levels of enantioselectivity. Importantly, the findings suggest a new strategy for the future creation of enantioselective C H/C H coupling reactions. 相似文献
13.
Chiral Counteranion Strategy for Asymmetric Oxidative C(sp3)H/C(sp3)H Coupling: Enantioselective α‐Allylation of Aldehydes with Terminal Alkenes
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Pu‐Sheng Wang Hua‐Chen Lin Yu‐Jia Zhai Zhi‐Yong Han Prof. Dr. Liu‐Zhu Gong 《Angewandte Chemie (International ed. in English)》2014,53(45):12218-12221
The first enantioselective α‐allylation of aldehydes with terminal alkenes has been realized by combining asymmetric counteranion catalysis and palladium‐catalyzed allylic C? H activation. This method can tolerate a wide scope of α‐branched aromatic aldehydes and terminal alkenes, thus affording allylation products in high yields and with good to excellent levels of enantioselectivity. Importantly, the findings suggest a new strategy for the future creation of enantioselective C? H/C? H coupling reactions. 相似文献
14.
Sumin Lee Dr. Natthawat Semakul Prof. Dr. Tomislav Rovis 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4995-4999
We report a RhIII-catalyzed regio- and diastereoselective synthesis of δ-lactams from readily available acrylamide derivatives and unactivated alkenes. The reaction provides a rapid route to a diverse set of δ-lactams in good yield and stereoselectivity, which serve as useful building blocks for substituted piperidines. The regioselectivity of the reaction with unactivated terminal alkene is significantly improved by using Cpt ligand on the RhIII catalyst. The synthetic utility of the reaction is demonstrated by the preparation of a potential drug candidate containing a trisubstituted piperidine moiety. Mechanistic studies show that the reversibility of the C−H activation depends on the choice of Cp ligand on the RhIII catalyst. The irreversible C−H activation is observed and becomes turnover-limiting with [CptRhCl2]2 as catalyst. 相似文献
15.
Dr. Tatsuya Yanagisawa Prof. Dr. Yoshiyuki Mizuhata Prof. Dr. Norihiro Tokitoh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(44):11273-11278
The reversible addition of olefins to a phosphanylalumane, P−Al single-bond species, was investigated. The P−Al bond added to ethylene and relatively small terminal alkenes (propylene and hex-1-ene) at room temperature to give the corresponding alkene adducts. Heating the terminal alkene adducts released the corresponding alkenes and regenerated the P−Al bond, but no release of ethylene was observed even under vacuum conditions. The reactivity of ethylene adduct as a new saturated C2 vicinal P/Al-based FLP was also investigated. The ethylene adduct was found to undergo complexation with nitriles to give the corresponding nitrile adducts to the Al center, which retained the ethylene tether as in the case of the corresponding P/B-based FLP. However, the reactivity of ethylene toward CO2 and benzaldehyde differed from that of the P/B system giving the corresponding adducts. 相似文献
16.
Michael Warsitz Prof. Dr. Sven Doye 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(66):15121-15125
The regioselective conversion of alkyl-substituted alkenes into linear hydroaminoalkylation products represents a strongly desirable synthetic transformation. In particular, such conversions of N-methylamine derivatives are of great scientific interest, because they would give direct access to important amines with unbranched alkyl chains. Herein, we present a new one-pot procedure that includes an initial alkene hydroaminoalkylation with an α-silylated amine substrate and a subsequent protodesilylation reaction that delivers linear hydroaminoalkylation products with high selectivity from simple alkyl-substituted alkenes. For that purpose, new titanium catalysts have been developed, which are able to activate the α-C−H bond of more challenging α-silylated amine substrates. In addition, a direct relationship between the ligand structure of the new catalysts and the obtained regioselectivity is described. 相似文献
17.
Tingting Chen Jassmin Lahbi Prof. Gianluigi Broggini Dr. Alexandre Pradal Prof. Giovanni Poli 《European journal of organic chemistry》2023,26(8):e202201493
Two previously unknown protocols for Pd-catalyzed allylic C−H sulfonylation of terminal alkenes have been developed. While the former consists of a direct Pd(II)-catalyzed oxidative C−H allylic sulfonylation in the presence of sulfinate anions, the latter involves a sequential one-pot Pd(II)-catalyzed C−H allylic acetoxylation followed by a Pd(0)-catalyzed sulfonylation. The scope of both protocols was studied on 25 examples. 相似文献
18.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(6):1636-1640
A unique Ir complex (tBuNCCP)Ir with the pyridine–phosphine pincer as the sole ligand, featuring a dual agostic interaction between the Ir and two σ C−H bonds from a t Bu substituent, has been prepared. This complex exhibits exceptionally high activity and excellent regio‐ and stereoselectivity for monoisomerization of 1‐alkenes to trans ‐2‐alkenes with wide functional‐group tolerance. Reactions can be performed in neat reactant on a more than 100 gram scale using 0.005 mol % catalyst loadings with turnover numbers up to 19000. 相似文献
19.
Dr. Yuxiang Zhu Matthew J. S. Smith Wenbin Tu Prof. John F. Bower 《Angewandte Chemie (International ed. in English)》2023,62(16):e202301262
TFA promoted deprotection of O−Ts activated N-Boc hydroxylamines triggers aminofunctionalization-based polycyclizations of tethered alkenes. The processes involve intramolecular stereospecific aza-Prilezhaev alkene aziridination in advance of stereospecific C−N cleavage by a pendant nucleophile. Using this approach, a wide range of fully intramolecular alkene anti-1,2-difunctionalizations can be achieved, including diaminations, amino-oxygenations and amino-arylations. Trends associated with the regioselectivity of the C−N cleavage step are outlined. The method provides a broad and predictable platform for accessing diverse C(sp3)-rich polyheterocycles of relevance to medicinal chemistry. 相似文献
20.
Sean R. Gitter Dr. Wei Pin Teh Dr. Xuejin Yang Alexander F. Dohoda Prof. Dr. Forrest E. Michael Prof. Dr. Andrew J. Boydston 《Angewandte Chemie (International ed. in English)》2023,62(23):e202303174
Post-polymerization modification (PPM) via direct C−H functionalization is a powerful synthetic strategy to convert polymer feed-stocks into value-added products. We found that a metal-free, Se-catalyzed allylic C−H amination provided an efficient method for PPM of polynorbornenes (PNBs) produced via ring-opening metathesis polymerization. Inherent to the mechanism of the allylic amination, PPM on PNBs preserved the alkene functional groups along the polymer backbone, while also avoiding transposition of the double bonds. Amination using a series of aryl sulfonamides led to good control over the degree of functionalization, access to a range of functionalities, and tunable thermal properties from the resulting polymers. 相似文献