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Enantioselective Synthesis of α‐Secondary and α‐Tertiary Piperazin‐2‐ones and Piperazines by Catalytic Asymmetric Allylic Alkylation 下载免费PDF全文
Katerina M. Korch Dr. Christian Eidamshaus Dr. Douglas C. Behenna Dr. Sangkil Nam Prof. Dr. David Horne Prof. Dr. Brian M. Stoltz 《Angewandte Chemie (International ed. in English)》2015,54(1):179-183
The asymmetric palladium‐catalyzed decarboxylative allylic alkylation of differentially N‐protected piperazin‐2‐ones allows the synthesis of a variety of highly enantioenriched tertiary piperazine‐2‐ones. Deprotection and reduction affords the corresponding tertiary piperazines, which can be employed for the synthesis of medicinally important analogues. The introduction of these chiral tertiary piperazines resulted in imatinib analogues which exhibited comparable antiproliferative activity to that of their corresponding imatinib counterparts. 相似文献
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《化学:亚洲杂志》2017,12(2):212-215
A new type of nucleophile, a 3‐imino nitrile carbanion generated in situ by Thorpe reaction of acetonitrile with a base, was developed successfully and applied in a Pd‐catalyzed asymmetric allylic alkylation with mono‐substituted allyl reagents under Pd/SIOCPhox catalysis, affording β‐enaminonitrile products in high yields with excellent regio‐ and enantioselectivities. 相似文献
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Asymmetric Allylic Alkylation of β‐Ketoesters with Allylic Alcohols by a Nickel/Diphosphine Catalyst 下载免费PDF全文
Dr. Yusuke Kita Dr. Rahul D. Kavthe Hiroaki Oda Prof. Dr. Kazushi Mashima 《Angewandte Chemie (International ed. in English)》2016,55(3):1098-1101
Asymmetric allylic alkylation of β‐ketoesters with allylic alcohols catalyzed by [Ni(cod)2]/(S)‐H8‐BINAP was found to be a superior synthetic protocol for constructing quaternary chiral centers at the α‐position of β‐ketoesters. The reaction proceeded in high yield and with high enantioselectivity using various β‐ketoesters and allylic alcohols, without any additional activators. The versatility of this methodology for accessing useful and enantioenriched products was demonstrated. 相似文献
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Carina I. Jette Z. Jaron Tong Ryan G. Hadt Brian M. Stoltz 《Angewandte Chemie (International ed. in English)》2020,59(5):2033-2038
Herein, we report a Cu‐catalyzed enantioselective allylic alkylation using a γ‐butyrolactone‐derived silyl ketene acetal. Critical to the development of this work was the identification of a novel mono‐picolinamide ligand with the appropriate steric and electronic properties to afford the desired products in high yield (up to 96 %) and high ee (up to 95 %). Aryl, aliphatic, and unsubstituted allylic chlorides bearing a broad range of functionality are well‐tolerated. Spectroscopic studies reveal that a CuI species is likely the active catalyst, and DFT calculations suggest ligand sterics play an important role in determining Cu coordination and thus catalyst geometry. 相似文献
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Chiral Primary Amine/Palladium Dual Catalysis for Asymmetric Allylic Alkylation of β‐Ketocarbonyl Compounds with Allylic Alcohols 下载免费PDF全文
Han Zhou Dr. Long Zhang Changming Xu Prof. Dr. Sanzhong Luo 《Angewandte Chemie (International ed. in English)》2015,54(43):12645-12648
An efficient dual catalytic system composed of a chiral primary amine and a palladium complex was developed to promote the direct asymmetric allylic alkylation (AAA) of β‐ketocarbonyl compounds. In particular, the synergistic dual catalytic system enabled the AAA reaction of challenging acyclic aliphatic ketones, such as β‐ketocarbonyl compounds and 1,3‐diketones. 相似文献
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Quaternary stereocenters are of great importance to the three-dimensionality and enhanced properties of new molecules, but the synthetic challenges in creating quaternary stereocenters greatly hinder their wide use in drug discovery, organic material design, and natural product synthesis. The asymmetric allylic alkylation (AAA) of allylic substrates has proven to be a powerful methodology for enantioselective formation of structure skeletons bearing single or more quaternary carbon centers in modern asymmetric organocatalysis. AAA has certain advantages in constructing the tetrasubstituted stereocenters, including but not limited to mild reactive conditions, effective reaction rates, new functional group introduction, and carbon chains length extension. This review outlines the key considerations in the application of AAA reactions and summarizes the recent progress of AAA reactions in the enantioselective synthesis of products containing quaternary stereocenters. Meanwhile, a detailed discussion of the AAA reactions such as ligands, scope of substrates, transformations and the general reaction mechanisms is also provided. We hope this review could stimulate further advances in much broader areas, including organic synthesis, asymmetric catalysis, C−H activation, and symmetrical pharmaceutical chemistry. 相似文献
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Enantioselective Pd‐Catalyzed Allylic Alkylation Reactions of Dihydropyrido[1,2‐a]indolone Substrates: Efficient Syntheses of (−)‐Goniomitine, (+)‐Aspidospermidine,and (−)‐Quebrachamine 下载免费PDF全文
Beau P. Pritchett Jun Kikuchi Dr. Yoshitaka Numajiri Prof. Dr. Brian M. Stoltz 《Angewandte Chemie (International ed. in English)》2016,55(43):13529-13532
The successful application of dihydropyrido[1,2‐a]indolone (DHPI) substrates in Pd‐catalyzed asymmetric allylic alkylation chemistry facilitates rapid access to multiple alkaloid frameworks in an enantioselective fashion. Strategic bromination at the indole C3 position greatly improved the allylic alkylation chemistry and enabled a highly efficient Negishi cross‐coupling downstream. The first catalytic enantioselective total synthesis of (?)‐goniomitine, along with divergent formal syntheses of (+)‐aspidospermidine and (?)‐quebrachamine, are reported herein. 相似文献
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New chiral N,S-ligands with oxazoline and thiophenyl sub-stituents at benzene ring and benzylic postition have been pre-pared and applied in palladium-catalyzed asymmetric allylic alkylation reaction to provide the product with high yield and entantioselectivity (82%-93%)ee. 相似文献
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Dr. Javier Mazuela Dr. Oscar Pàmies Prof. Montserrat Diéguez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2416-2432
A library of phosphite‐pyridine ligands L1 – L12 a – g has been successfully applied for the first time in the Pd‐catalyzed allylic substitution reactions of several di‐ and trisubstituted substrates by using a wide range of C, N and O nucleophiles, among which are the little studied α‐substituted malonates, β‐diketones, and alkyl alcohols. The highly modular nature of this ligand library enables the substituents/configuration at the ligand backbone, and the substituents/configurations at the biaryl phosphite moiety to be easily and systematically varied. We found that the introduction of an enantiopure biaryl phosphite moiety played an essential role in increasing the versatility of the Pd‐catalytic systems. Enantioselectivities were therefore high for several hindered and unhindered di‐ and trisubstituted substrates by using a wide range of C, N and O nucleophiles. Of particular note were the high enantioselectivities (up to>99 % ee) and high activities obtained for the trisubstituted substrates S6 and S7 , which compare favorably with the best that have been reported in the literature. We have also extended the use of these new catalytic systems in alternative environmentally friendly solvents such as propylene carbonate and ionic liquids. Studies on the Pd‐π‐allyl intermediates provide a deeper understanding of the effect of ligand parameters on the origin of enantioselectivity. 相似文献
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Ajmal Khan Heng Zhao Meina Zhang Shahid Khan Depeng Zhao 《Angewandte Chemie (International ed. in English)》2020,59(3):1340-1345
Chiral sulfones are of great importance in medicinal chemistry and chemical synthesis. Efficient methods for preparing enantiomerically enriched sulfone‐containing molecules can therefore be of significant value; such methods, however, are uncommon. Herein, we report the first general palladium‐catalyzed sulfonylation of vinyl cyclic carbonates with sodium sulfinates. A series of enantiomerically enriched tertiary allylic sulfones were synthesized in good yields with excellent enantiomeric ratios. Both aliphatic‐ and aryl‐substituted vinyl cyclic carbonates are suitable reactants with excellent results. This reaction features broad substrates scope, readily available starting materials, excellent regio‐ and enantioselectivity, and synthesis of sulfone‐bearing quaternary carbon stereocenters. Through the sulfonylation of geranyl derived cyclic carbonate 1 h , we achieve the formal total synthesis of (+)‐agelasidine A. 相似文献
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Iridium‐Catalyzed Diastereoselective and Enantioselective Allylic Substitutions with Acyclic α‐Alkoxy Ketones 下载免费PDF全文
Xingyu Jiang Wenyong Chen Prof. John F. Hartwig 《Angewandte Chemie (International ed. in English)》2016,55(19):5819-5823
The asymmetric alkylation of acyclic ketones is a longstanding challenge in organic synthesis. Reported herein are diastereoselective and enantioselective allylic substitutions with acyclic α‐alkoxy ketones catalyzed by a metallacyclic iridium complex to form products with contiguous stereogenic centers derived from the nucleophile and electrophile. These reactions occur between allyl methyl carbonates and unstabilized copper(I) enolates generated in situ from acyclic α‐alkoxy ketones. The resulting products can be readily converted into enantioenriched tertiary alcohols and tetrahydrofuran derivatives without erosion of enantiomeric purity. 相似文献