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Dr. Jinhu Wei Dr. Liangliang Wu Dr. Hai-Xu Wang Dr. Xiting Zhang Dr. Chun-Wai Tse Dr. Cong-Ying Zhou Dr. Jie-Sheng Huang Prof. Dr. Chi-Ming Che 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(38):16704-16714
Reliable methods for enantioselective cis-dihydroxylation of trisubstituted alkenes are scarce. The iron(II) complex cis-α-[FeII(2-Me2-BQPN)(OTf)2], which bears a tetradentate N4 ligand (Me2-BQPN=(R,R)-N,N′-dimethyl-N,N′-bis(2-methylquinolin-8-yl)-1,2-diphenylethane-1,2-diamine), was prepared and characterized. With this complex as the catalyst, a broad range of trisubstituted electron-deficient alkenes were efficiently oxidized to chiral cis-diols in yields of up to 98 % and up to 99.9 % ee when using hydrogen peroxide (H2O2) as oxidant under mild conditions. Experimental studies (including 18O-labeling, ESI-MS, NMR, EPR, and UV/Vis analyses) and DFT calculations were performed to gain mechanistic insight, which suggested possible involvement of a chiral cis-FeV(O)2 reaction intermediate as an active oxidant. This cis-[FeII(chiral N4 ligand)]2+/H2O2 method could be a viable green alternative/complement to the existing OsO4-based methods for asymmetric alkene dihydroxylation reactions. 相似文献
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Highly Enantioselective Iron‐Catalyzed cis‐Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an FeIII‐OOH Reactive Intermediate 下载免费PDF全文
Dr. Chao Zang Dr. Yungen Liu Dr. Zhen‐Jiang Xu Chun‐Wai Tse Dr. Xiangguo Guan Jinhu Wei Dr. Jie‐Sheng Huang Prof. Dr. Chi‐Ming Che 《Angewandte Chemie (International ed. in English)》2016,55(35):10253-10257
The development of environmentally benign catalysts for highly enantioselective asymmetric cis‐dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′‐dimethyl‐N,N′‐bis(2‐methyl‐8‐quinolyl)‐cyclohexane‐1,2‐diamine) as a catalyst, cis‐diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2 as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2” method is applicable to both (E)‐alkenes and terminal alkenes (24 examples >80 % ee, up to 1 g scale). Mechanistic studies, including 18O‐labeling, UV/Vis, EPR, ESI‐MS analyses, and DFT calculations lend evidence for the involvement of chiral FeIII‐OOH active species in enantioselective formation of the two C?O bonds. 相似文献
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Herein, the iron‐catalyzed reduction of a variety of alkynes with silanes as a reductant has been examined. With a straightforward catalyst system composed of diiron nonacarbonyl and tributyl phosphane, excellent yields and chemoselectivities (>99 %) were obtained for the formation of the corresponding alkenes. After studying the reaction conditions, and the scope and limitations of the reaction, several attempts were undertaken to shed light on the reaction mechanism. 相似文献
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Dr. Maialen Espinal‐Viguri Callum R. Woof Dr. Ruth L. Webster 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11605-11608
Iron‐catalyzed hydroboration (HB) of alkenes and alkynes is reported. A simple change in ligand structure leads to an extensive change in catalyst activity. Reactions proceed efficiently over a wide range of challenging substrates including activated, unactivated and sterically encumbered motifs. Conditions are mild and do not require the use of reducing agents or other additives. Large excesses of borating reagent are not required, allowing control of chemo‐ and regioselectivity in the presence of multiple double bonds. Mechanistic insight reveals that the reaction is likely to proceed via a highly reactive iron hydride intermediate. 相似文献
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Yong‐An Yuan Deng‐Fu Lu Yun‐Rong Chen Prof. Hao Xu 《Angewandte Chemie (International ed. in English)》2016,55(2):534-538
Reported herein is a new iron‐catalyzed diastereoselective olefin diazidation reaction which occurs at room temperature (1–5 mol % of catalysts and d.r. values of up to >20:1). This method tolerates a broad range of both unfunctionalized and highly functionalized olefins, including those that are incompatible with existing methods. It also provides a convenient approach to vicinal primary diamines as well as other synthetically valuable nitrogen‐containing building blocks which are difficult to obtain with alternative methods. Preliminary mechanistic studies suggest that the reaction may proceed through a new mechanistic pathway in which both Lewis acid activation and iron‐enabled redox‐catalysis are crucial for selective azido‐group transfer. 相似文献
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Jonathan R. Carney Barry R. Dillon Leonie Campbell Dr. Stephen P. Thomas 《Angewandte Chemie (International ed. in English)》2018,57(33):10620-10624
The manganese‐catalyzed hydrosilylation and hydroboration of alkenes has been developed using a single manganese(II) precatalyst and reaction protocol. Both reactions proceed with excellent control of regioselectivity and in high yields across a variety of sterically and electronically differentiated substrates (25 examples). Alkoxide activation, using NaOtBu, was key to precatalyst activation and reactivity. Catalysis was achieved across various functional groups and on gram‐scale for both the developed methodologies with catalysts loadings as low as 0.5 mol %. 相似文献
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Bianca Bitterlich Gopinathan Anilkumar Dr. Feyissa Gadissa Gelalcha Dr. Björn Spilker Dr. Anne Grotevendt Ralf Jackstell Dr. Man Kin Tse Dr. Matthias Beller Prof. Dr. 《化学:亚洲杂志》2007,2(4):521-529
The development of inexpensive and practical iron catalysts for the environmentally benign epoxidation of olefins with hydrogen peroxide as terminal oxidant is described. By systematic variation of ligands, metal sources, and reaction conditions, it was discovered that FeCl3?6H2O in combination with pyridine‐2,6‐dicarboxylic acid and different amines shows high reactivity and excellent selectivity towards the epoxidation of aromatic olefins and moderate reactivity towards that of aliphatic olefins. 相似文献
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Ting Liu Yunhui Yang Congyang Wang 《Angewandte Chemie (International ed. in English)》2020,59(34):14256-14260
Transition‐metal‐catalyzed hydroarylation of unactivated alkenes with strategic use of remote coordinating functional groups has received significant attention recently to address the issues of both low reactivity and poor selectivity. The bidentate 8‐aminoquinoline amide group is the most successfully adopted in unactivated alkenes for Pd and Ni catalysis. We describe the first manganese‐catalyzed hydroarylation of unactivated alkenes bearing diverse simple functionalities with arylboronic acids. A series of δ‐ and γ‐arylated amides, ketones, pyridines, and amines was accessed with excellent regioselectivity and in high yields. Hydroalkenylation of unactivated alkenes was also shown to be applicable under this manganese‐catalysis regime. The method features earth‐abundant manganese catalysis, easily available substrates, broad functional‐group tolerance, and excellent regioselective control. 相似文献
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Michael T. Bovino Timothy W. Liwosz Nicole E. Kendel Dr. Yan Miller Dr. Nina Tyminska Prof. Eva Zurek Prof. Sherry R. Chemler 《Angewandte Chemie (International ed. in English)》2014,53(25):6383-6387
Chiral saturated oxygen heterocycles are important components of bioactive compounds. Cyclization of alcohols onto pendant alkenes is a direct route to their synthesis, but few catalytic enantioselective methods enabling cyclization onto unactivated alkenes exist. Herein reported is a highly efficient copper‐catalyzed cyclization of γ‐unsaturated pentenols which terminates in C? C bond formation, a net alkene carboetherification. Both intra‐ and intermolecular C? C bond formations are demonstrated, thus yielding functionalized chiral tetrahydrofurans as well as fused‐ring and bridged‐ring oxabicyclic products. Transition‐state calculations support a cis‐oxycupration stereochemistry‐determining step. 相似文献
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Wing‐Ping Yip Dr. Chi‐Ming Ho Dr. Nianyong Zhu Dr. Tai‐Chu Lau Prof. Dr. Chi‐Ming Che Prof. Dr. 《化学:亚洲杂志》2008,3(1):70-77
A simple and green method that uses [Ru(Me3tacn)Cl3] ( 1 ; Me3tacn=N,N′,N′′‐trimethyl‐1,4,7‐triazacyclononane) as catalyst, aqueous H2O2 as the terminal oxidant, and Al2O3 and NaCl as additives is effective in the cis‐dihydroxylation of alkenes in aqueous tert‐butanol. Unfunctionalized alkenes, including cycloalkenes, aliphatic alkenes, and styrenes (14 examples) were selectively oxidized to their corresponding cis‐diols in good to excellent yield (70–96 %) based on substrate conversions of up to 100 %. The preparation of cis‐1,2‐cycloheptanediol (119 g, 91 % yield) and cis‐1,2‐cyclooctanediol (128 g, 92 % yield) from cycloheptene and cyclooctene, respectively, on the 1‐mol scale can be achieved by scaling up the reaction without modification. Results from Hammett correlation studies on the competitive oxidation of para‐substituted styrenes (ρ=?0.97, R=0.988) and the detection of the cycloadduct [(Me3tacn)ClRuHO2(C8H14)]+ by ESI‐MS for the 1 ‐catalyzed oxidation of cyclooctene to cis‐1,2‐cyclooctanediol are similar to those of the stoichiometric oxidation of alkenes by cis‐[(Me3tacn)(CF3CO2)RuVIO2]+ through [3+2] cycloaddition (W.‐P. Yip, W.‐Y. Yu, N. Zhu, C.‐M. Che, J. Am. Chem. Soc. 2005 , 127, 14239). 相似文献
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M. Sc. Isabel T. Alt Prof. Dr. Bernd Plietker 《Angewandte Chemie (International ed. in English)》2016,55(4):1519-1522
The nucleophilic iron complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the direct intramolecular C?H amination of α‐azidobiaryls and (azidoaryl)alkenes into the corresponding carbazoles and indoles, respectively, under mild conditions and with low catalyst loadings. These features and the broad functional‐group tolerance render this method a particularly attractive alternative to established noble‐metal‐based procedures. 相似文献
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Iron‐Catalyzed Regioselective Transfer Hydrogenative Couplings of Unactivated Aldehydes with Simple Alkenes 下载免费PDF全文
Yan‐Long Zheng Yan‐Yao Liu Yi‐Mei Wu Yin‐Xia Wang Yu‐Tong Lin Prof. Dr. Mengchun Ye 《Angewandte Chemie (International ed. in English)》2016,55(21):6315-6318
An FeBr3‐catalyzed reductive coupling of various aldehydes with alkenes that proceeds through a direct hydride transfer pathway has been developed. With iPrOH as the hydrogen donor under mild conditions, previously challenging coupling reactions of unactivated alkyl and aryl aldehydes with simple alkenes, such as styrene derivatives and α‐olefins, proceeded smoothly to furnish a diverse range of functionalized alcohols with complete linear regioselectivity. 相似文献
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Jun‐Jie Shen Prof. Shou‐Fei Zhu Dr. Yan Cai Huan Xu Xiu‐Lan Xie Prof. Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2014,53(48):13188-13191
An iron‐catalyzed asymmetric intramolecular cyclopropanation was realized in high yields and excellent enantioselectivity (up to 97 % ee) by using the iron complexes of chiral spiro‐bisoxazoline ligands as catalysts. The superiority of iron catalysts exhibited in this reaction demonstrated the potential abilities of this sustainable metal in asymmetric carbenoid transformation reactions. 相似文献
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Highly Chemo‐, Regio‐, and Enantioselective Rhodium‐Catalyzed Cross‐Cyclotrimerization of Two Different Alkynes with Alkenes 下载免费PDF全文
Jun Hara Mana Ishida Masayuki Kobayashi Prof. Dr. Keiichi Noguchi Prof. Dr. Ken Tanaka 《Angewandte Chemie (International ed. in English)》2014,53(11):2956-2959
It has been established that a cationic rhodium(I)/(R)‐tol‐binap complex catalyzes the cross‐cyclotrimerization of silylacetylenes, di‐tert‐butyl acetylenedicarboxylates, and acrylamides with excellent chemo‐, regio‐, and enantioselectivities. Unsymmetrical alkynoates can also be employed in place of di‐tert‐butyl acetylenedicarboxylate for this process, but with reduced chemoselectivity. 相似文献
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Jianhui Chen Biao Cheng Minyi Cao Prof. Zhan Lu 《Angewandte Chemie (International ed. in English)》2015,54(15):4661-4664
The highly regio‐ and enantioselective iron‐catalyzed anti‐Markovnikov hydrosilylation of 1,1‐disubstituted aryl alkenes was developed using iminopyridine oxazoline ligands to afford chiral organosilanes. Additional derivatization of these products lead to chiral organosilanols, cyclic silanes, phenol derivatives, and 3‐substituted 2,3‐dihydrobenzofurans. 相似文献
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Thomas Gendrineau Nicolas Demoulin Laure Navarre Jean‐Pierre Genet Prof. Sylvain Darses Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(18):4710-4715
Efficient and general conditions for the formation of stereodefined trisubstituted alkenes by using the rhodium‐catalyzed reaction of unactivated Baylis–Hillman adducts with either organoboronic acids or potassium trifluoro(organo)borates are reported (see scheme).