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1.
Ming Chen Xucai Wang Pengfei Yang Xun Kou Zhi‐Hui Ren Zheng‐Hui Guan 《Angewandte Chemie (International ed. in English)》2020,59(29):12199-12205
Reported herein is the development of the first enantioselective monodentate ligand assisted Pd‐catalyzed domino Heck carbonylation reaction with CO. The highly enantioselective domino Heck carbonylation of N‐aryl acrylamides and various nucleophiles, including arylboronic acids, anilines, and alcohols, in the presence of CO was achieved. A novel monodentate phosphoramidite ligand, Xida‐Phos, has been developed for this reaction and it displays excellent reactivity and enantioselectivity. The reaction employs readily available starting materials, tolerates a wide range of functional groups, and provides straightforward access to a diverse array of enantioenriched oxindoles having β‐carbonyl‐substituted all‐carbon quaternary stereocenters, thus providing a facile and complementary method for the asymmetric synthesis of bioactive hexahydropyrroloindole and its dimeric alkaloids. 相似文献
2.
Ming Chen Xucai Wang Pengfei Yang Xun Kou Zhi-Hui Ren Prof. Dr. Zheng-Hui Guan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):12297-12303
Reported herein is the development of the first enantioselective monodentate ligand assisted Pd-catalyzed domino Heck carbonylation reaction with CO. The highly enantioselective domino Heck carbonylation of N-aryl acrylamides and various nucleophiles, including arylboronic acids, anilines, and alcohols, in the presence of CO was achieved. A novel monodentate phosphoramidite ligand, Xida-Phos, has been developed for this reaction and it displays excellent reactivity and enantioselectivity. The reaction employs readily available starting materials, tolerates a wide range of functional groups, and provides straightforward access to a diverse array of enantioenriched oxindoles having β-carbonyl-substituted all-carbon quaternary stereocenters, thus providing a facile and complementary method for the asymmetric synthesis of bioactive hexahydropyrroloindole and its dimeric alkaloids. 相似文献
3.
Hui Yu Guoying Zhang Prof. Dr. Hanmin Huang 《Angewandte Chemie (International ed. in English)》2015,54(37):10912-10916
A fundamentally novel approach to bioactive quinolizinones is based on the palladium‐catalyzed intramolecular cyclocarbonylation of allylamines. [Pd(Xantphos)I2], which features a very large bite angle, has been found to facilitate the rapid carbonylation of azaarene‐substituted allylamines into bioactive quinolizinones in good to excellent yields. This transformation represents the first dearomative carbonylation and is proposed to proceed by palladium‐catalyzed C? N bond activation, dearomatization, CO insertion, and a Heck reaction. 相似文献
4.
Hui Yu Guoying Zhang Hanmin Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(37):11062-11066
A fundamentally novel approach to bioactive quinolizinones is based on the palladium‐catalyzed intramolecular cyclocarbonylation of allylamines. [Pd(Xantphos)I2], which features a very large bite angle, has been found to facilitate the rapid carbonylation of azaarene‐substituted allylamines into bioactive quinolizinones in good to excellent yields. This transformation represents the first dearomative carbonylation and is proposed to proceed by palladium‐catalyzed C N bond activation, dearomatization, CO insertion, and a Heck reaction. 相似文献
5.
Enantioselective NH Insertion Reaction of α‐Aryl α‐Diazoketones: An Efficient Route to Chiral α‐Aminoketones
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Bin Xu Prof. Shou‐Fei Zhu Xiao‐Dong Zuo Zhi‐Chao Zhang Prof. Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2014,53(15):3913-3916
A highly enantioselective N? H insertion reaction of α‐diazoketones was developed by using cooperative catalysis by dirhodium(II) carboxylates and chiral spiro phosphoric acids. The insertion reaction provides a new access route to diverse chiral α‐aminoketones, which are versatile building blocks in organic synthesis, with fast reaction rates, good yields and high enantioselectivity under mild and neutral conditions. 相似文献
6.
The enantioselective formal synthesis of (?)-aurantioclavine is described. The core tricyclic skeleton was synthesized using a Pd-catalyzed Heck insertion–allylic amination cascade. The stereocenter was constructed by a highly enantioselective organocatalytic asymmetric aziridination reaction. 相似文献
7.
Noncovalent Substrate‐Directed Enantioselective Heck Reactions: Synthesis of S‐ and P‐Stereogenic Heterocycles
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Tomaz H. D. Chorro Dr. Gabriel Heerdt Prof. Dr. Carlos Roque D. Correia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11205-11209
S‐ and P‐Stereogenic heterocycles were synthesized by a remarkably simple enantioselective Heck desymmetrization reaction based on the unprecedented noncovalent directing effect of S=O and P=O functionalities. Selected prochiral symmetric substrates were efficiently arylated using the recently disclosed chiral PyraBOx ligand under mild and open‐flask reaction conditions. Several five‐membered aryl‐ sulfones, sulfoxides, and phosphine oxides were synthesized in good to excellent yields, in good to high diastereoselectivity, and enantiomeric ratios up to 98:2. Theoretical calculations also support the noncovalent directing effect of the S=O and P=O functionalities during the arylation process. 相似文献
8.
Iimura S Overman LE Paulini R Zakarian A 《Journal of the American Chemical Society》2006,128(40):13095-13101
A convergent, enantioselective total synthesis of (+)-guanacastepene N was developed that features a 7-endo Heck cyclization as the key step. In the course of this synthesis, short syntheses of the enantiomerically pure cyclopentenone and cyclohexene building blocks 5 and 6, which constitute A and C ring fragments of guanacastepene N, were developed. These fragments were linked by a challenging conjugate addition reaction that also generated the C11 quaternary carbon stereocenter. Regioselective 7-endo Heck cyclization gave rise to a tricyclic intermediate, which was elaborated to complete the first total synthesis of guanacastepene N and the second enantioselective total synthesis of a guanacastepene natural product. 相似文献
9.
Prof. Dr. Lutz F. Tietze Stefan Jackenkroll Dr. Christian Raith Dr. Dirk A. Spiegl Johannes R. Reiner Maria Claudia Ochoa Campos 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(15):4876-4882
For the synthesis of (?)‐diversonol (ent‐ 1 ), an enantioselective domino‐Wacker/carbonylation/methoxylation reaction and an enantioselective Wacker oxidation were used to give the chroman in high yield and 96 % and 93 % ee, respectively. Dihydroxylation at the vinyl moiety using the Sharpless procedure and a Wittig–Horner reaction followed by hydrogenation, benzylic oxidation, and an intramolecular acylation provided the tetrahydroxanthenone, from which ent‐ 1 is accessible in a few steps. Furthermore, the synthesis of the diastereomeric diversonol rac‐1,9 a‐epi‐diversonol (rac‐ 41 ) is also described. 相似文献
10.
Qin Xiong Dongdong Xu Chunhui Shan Song Liu Yixin Luo Fenru Liu Shihan Liu Yu Lan Ruopeng Bai 《化学:亚洲杂志》2019,14(5):655-661
Palladium (Pd)‐catalyzed radical oxidative C?H carbonylation of alkanes is a useful method for functionalizing hydrocarbons, but there is still a lack of understanding of the mechanism, which restricts the application of this reaction. In this work, density functional theory (DFT) calculations were carried out to study the mechanism for a Pd‐catalyzed radical esterification reaction. Two plausible reaction pathways have been proposed and validated by DFT calculations. The computational results reveal that the generated alkyl radical prefers to add to the carbon monoxide (CO) molecule to form a carbonyl radical before bonding with the Pd species. Radical addition onto Pd followed by CO migratory insertion was unfavorable owing to the high energy barrier of the migratory insertion step. The regioselectivity of the C(sp3)?H carbonylation was also investigated by DFT. The results show that the regioselectivity is controlled by both the bond dissociation energy of the reacting C?H bond and the stability of the corresponding generated carbon radical. Competitive side reactions also affected the yield and regioselectivity owing to the rapid consumption of the stable radical intermediate. 相似文献
11.
Denis Kiely 《Journal of organometallic chemistry》2003,687(2):545-561
The synthesis of two novel cyclisation substrates for the asymmetric intramolecular Heck reaction is reported. Their cyclisation, in addition to a known substrate for cis-decalin formation, were tested with palladium complexes of BINAP and heterobidentate oxazoline-containing ligands. In general BINAP provides a more active catalyst system for the range of substrates tested although excellent enantioselectivities of up to 85% were obtained with the P,N ligands studied. A trend was noted whereby the t-leucine-derived oxazoline ligands were more reactive and enantioselective than the valine-derived analogues. Similarly, the diphenylphosphinoferrocenyloxazoline ligands were more reactive and selective than the corresponding diphenylphosphinophenyloxazoline ligands. 相似文献
12.
Bin Xu Shou‐Fei Zhu Xiao‐Dong Zuo Zhi‐Chao Zhang Qi‐Lin Zhou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(15):3994-3997
A highly enantioselective N H insertion reaction of α‐diazoketones was developed by using cooperative catalysis by dirhodium(II) carboxylates and chiral spiro phosphoric acids. The insertion reaction provides a new access route to diverse chiral α‐aminoketones, which are versatile building blocks in organic synthesis, with fast reaction rates, good yields and high enantioselectivity under mild and neutral conditions. 相似文献
13.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(12):3269-3273
A highly selective palladium‐catalyzed oxidative carbonylation/carbocyclization/alkoxycarbonylation of enallenols to afford spirolactones bearing an all‐carbon quaternary center was developed. This transformation involves the overall formation of three C−C bonds and one C−O bond through a cascade insertion of carbon monoxide (CO), an olefin, and CO. Preliminary experiments on chiral anion‐induced enantioselective carbonylation/carbocyclization of enallenols afforded spirolactones with moderate enantioselectivity. 相似文献
14.
General Olefin Synthesis by the Palladium‐Catalyzed Heck Reaction of Amides: Sterically Controlled Chemoselective NC Activation
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Guangrong Meng Prof. Dr. Michal Szostak 《Angewandte Chemie (International ed. in English)》2015,54(48):14518-14522
Metal‐catalyzed reactions of amides proceeding via metal insertion into the N? CO bond are severely underdeveloped due to resonance stabilization of the amide bond. Herein we report the first Heck reaction of amides proceeding via highly chemoselective N? CO cleavage catalyzed by Pd0 utilizing amide bond ground‐state destabilization. Conceptually, this transformation provides access to a myriad of metal‐catalyzed transformations of amides via metal insertion/decarbonylation. 相似文献
15.
Enantioselective Palladium‐Catalyzed Insertion of α‐Aryl‐α‐diazoacetates into the OH Bonds of Phenols
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Xiu‐Lan Xie Prof. Shou‐Fei Zhu Jun‐Xia Guo Yan Cai Prof. Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2014,53(11):2978-2981
A palladium‐catalyzed asymmetric O? H insertion reaction was developed. Palladium complexes with chiral spiro bisoxazoline ligands promoted the insertion of α‐aryl‐α‐diazoacetates into the O? H bond of phenols with high yield and excellent enantioselectivity under mild reaction conditions. This palladium‐catalyzed asymmetric O? H insertion reaction provided an efficient and highly enantioselective method for the preparation of synthetically useful optically active α‐aryl‐α‐aryloxyacetates. 相似文献
16.
通过密度泛函理论(DFT)研究了钯催化氧化N—H键羰基化反应合成1,3,4-噁二唑-2(3H)-酮杂环化合物的反应机理. 计算结果表明, 这一反应的催化循环包含N1—H活化、 羰基插入、 N2—H活化和还原消除4个阶段. 反应首先通过协同金属化/去质子化机理活化N1—H键, 然后羰基插入Pd—N1键生成稳定的六元金属环中间体, 随后通过一步反应直接发生N2—H键活化, 最后还原消除. 其中, 羰基插入是整个催化循环的决速步骤, 能垒为102.0 kJ/mol. 研究了配体效应和取代基效应, 其结果与已有的实验结果一致. 相似文献
17.
Gadolinium‐Catalyzed Regio‐ and Enantioselective Aminolysis of Aromatic trans‐2,3‐Epoxy Sulfonamides
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Dr. Chuan Wang Prof. Dr. Hisashi Yamamoto 《Angewandte Chemie (International ed. in English)》2015,54(30):8760-8763
The first enantioselective aminolysis of aromatic trans‐2,3‐epoxy sulfonamides has been accomplished, which was efficiently catalyzed by a Gd‐N,N′‐dioxide complex. Under the directing effect of the sulfonamide moiety the ring‐opening reaction proceeded selectively at the C‐3 position in a highly enantioselective manner furnishing various Ts‐ and SES‐protected 3‐amino‐3‐phenylpropan‐2‐olamines as products. 相似文献
18.
Jiayang Zhang Yangtian Yan Rong Hu Ting Li Wen‐Ju Bai Yang Yang 《Angewandte Chemie (International ed. in English)》2020,59(7):2860-2866
A novel palladium‐catalyzed Heck‐type reaction of thiocarbamates has been designed to construct bridged seven‐membered‐ring systems that are otherwise challenging to prepare. Taking advantage of this newly developed method, enantioselective syntheses of lyconadins A–E ( 1 – 5 ), lycopecurine ( 6 ), and dehydrolycopecurine ( 7 ) have been realized in a divergent fashion. Our synthetic strategy also features an intramolecular cyclization of a N‐chloroamine to forge the C6?N bond, a transannular Mannich‐type reaction of a cyclic nitrone to stitch the C4 and C13 together, and a cyclocondensation to deliver the (dihydro‐)pyridone motif. 相似文献
19.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(50):16112-16116
An asymmetric copper‐catalyzed alkylation of quinoline N ‐oxides with chiral Cu–alkyl species, generated by migratory insertion of a vinylarene into a chiral Cu−H complex, is reported. A variety of quinoline N ‐oxides and vinylarenes underwent this Cu‐catalyzed enantioselective alkylation reaction, affording the corresponding chiral alkylated N‐heteroarenes in high yield with high‐to‐excellent enantioselectivity. This enantioselective protocol represents the first general and practical approach to access a wide range of chiral alkylated quinolines. 相似文献
20.
Guangrong Meng Michal Szostak 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(48):14726-14730
Metal‐catalyzed reactions of amides proceeding via metal insertion into the N CO bond are severely underdeveloped due to resonance stabilization of the amide bond. Herein we report the first Heck reaction of amides proceeding via highly chemoselective N CO cleavage catalyzed by Pd0 utilizing amide bond ground‐state destabilization. Conceptually, this transformation provides access to a myriad of metal‐catalyzed transformations of amides via metal insertion/decarbonylation. 相似文献