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Development of Enantioselective Palladium‐Catalyzed Alkene Carboalkoxylation Reactions for the Synthesis of Tetrahydrofurans 下载免费PDF全文
Brett A. Hopkins Zachary J. Garlets Prof. Dr. John P. Wolfe 《Angewandte Chemie (International ed. in English)》2015,54(45):13390-13392
The Pd‐catalyzed coupling of γ‐hydroxyalkenes with aryl bromides affords enantiomerically enriched 2‐(arylmethyl)tetrahydrofuran derivatives in good yield and up to 96:4 e.r. This transformation was achieved through the development of a new TADDOL/2‐arylcyclohexanol‐derived chiral phosphite ligand. The transformations are effective with an array of different aryl bromides, and can be used for the preparation of products bearing quaternary stereocenters. 相似文献
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Efficient Synthesis of (−)‐Corynoline by Enantioselective Palladium‐Catalyzed α‐Arylation with Sterically Hindered Substrates 下载免费PDF全文
Dr. Xiaofeng Rao Dr. Naikai Li Heng Bai Chaodi Dai Dr. Zheng Wang Prof. Dr. Wenjun Tang 《Angewandte Chemie (International ed. in English)》2018,57(38):12328-12332
Sterically hindered substrates can be employed in an enantioselective palladium‐catalyzed α‐arylation with the chiral monophosphorus ligand BI‐DIME. This process enabled an efficient synthesis of the antidepressant (S)‐nafenodone, a four‐step enantioselective synthesis of the Sceletium alkaloid (+)‐sceletium A‐4, a concise five‐step enantioselective synthesis of (?)‐corynoline, as well as a three‐step preparation of (?)‐DeN‐corynoline. 相似文献
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Dr. Kei Kitamura Dr. Naoyuki Shimada Dr. Craig Stewart Dr. Abdurrahman C. Atesin Prof. Tülay A. Ateşin Prof. Dr. Marcus A. Tius 《Angewandte Chemie (International ed. in English)》2015,54(21):6288-6291
A Pd0‐catalyzed asymmetric Nazarov‐type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL‐derived phosphoramidite (TADDOL=α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one an all‐carbon‐atom quaternary stereocenter, in high yield and optical purity. It is noteworthy that the reaction does not require that substrates should be activated by aryl substituents. 相似文献
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Lei Wang Kenan Zhang Yuzhuo Wang Wenbo Li Mingjie Chen Junliang Zhang 《Angewandte Chemie (International ed. in English)》2020,59(11):4421-4427
Reported here is a highly efficient Pd/Xiang‐Phos catalyzed enantioselective carboetherification of alkenyl oximes with either aryl or alkenyl halides, delivering various chiral 3,5‐disubstituted and 3,5,5‐trisubstituted isoxazolines in good yields with up to 97 % ee. The sterically bulky and electron‐rich (S,Rs)‐ NMe‐X2 ligand is responsible for the excellent reactivities and enantioselectivities. The salient features of this transformation include mild reaction conditions, general substrate scope, good functional‐group tolerance, good yields, high enantioselectivities, easy scale‐up, and application in the late‐stage modification of bioactive compounds. The obtained products can be readily transformed into useful chiral 1,3‐aminoalcohols. 相似文献
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Highly Enantioselective Nickel‐Catalyzed Intramolecular Reductive Cyclization of Alkynones 下载免费PDF全文
Wenzhen Fu Ming Nie Aizhen Wang Ziping Cao Prof. Dr. Wenjun Tang 《Angewandte Chemie (International ed. in English)》2015,54(8):2520-2524
The first asymmetric nickel‐catalyzed intramolecular reductive cyclization of alkynones is reported. A P‐chiral monophosphine and triethylsilane were used as the ligand and the reducing reagent, respectively, to form a series of tertiary allylic alcohols bearing furan/pyran rings in excellent yields and enantioselectivities. This reaction has a broad substrate scope and enabled the efficient synthesis of dehydroxycubebin and chiral dibenzocyclooctadiene skeletons. 相似文献
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Diastereo‐ and Enantioselective Palladium‐Catalyzed Dearomative [3+2] Cycloaddition of 3‐Nitroindoles 下载免费PDF全文
Diastereo‐ and enantioselective cycloaddition of 3‐nitroindoles with vinyl aziridine was realized under Pd‐catalysis using commercially available Walphos as the ligand, affording pyrroloindolines in high yields with high diastereo‐ and enantioselectivities. The reaction can be scaled up to a gram scale and the reaction products are easily converted to amino pyrroloindoline and other pyrroloindoline derivatives. 相似文献
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Rhodium‐Catalyzed Arylative Cyclization for the Enantioselective Synthesis of (Trifluoromethyl)cyclobutanols 下载免费PDF全文
Thomas Johnson Ken‐Loon Choo Prof. Dr. Mark Lautens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(44):14194-14197
A rhodium‐catalyzed cyclization of 1‐(trifluoromethyl)‐4‐alkyn‐1‐ones with arylboronic acids is described to yield a novel class of small rings: (trifluoromethyl)cyclobutanols bearing an exocyclic double bond. The use of a rhodium/chiral diene complex allowed the reaction to proceed under mild conditions, often with high enantioselectivity. An X‐ray crystal structure was obtained confirming the formation of the four‐membered ring products. 相似文献
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Pd‐Catalyzed Enantiodivergent and Regiospecific phospha‐Michael Addition of Diphenylphosphine to 4‐oxo‐Enamides: Efficient Access to Chiral Phosphinocarboxamides and Their Analogues 下载免费PDF全文
Renta Jonathan Chew Xi‐Rui Li Dr. Yongxin Li Dr. Sumod A. Pullarkat Prof. Dr. Pak‐Hing Leung 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(12):4800-4804
The palladacycle‐catalyzed asymmetric P?H addition of 4‐oxo‐enamides has been developed, which provides efficient access to phosphinocarboxamides and their analogues. Solvent‐mediated reversal of stereoselectivity (ee from +96 % to ?92 %) was observed, and the underlying mechanism that allows facile access to both enantiomers of the product by judicious choice of solvents is revealed. 相似文献
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Palladium‐Catalyzed Enantioselective CH Arylation for the Synthesis of P‐Stereogenic Compounds 下载免费PDF全文
Zi‐Qi Lin Wei‐Zhen Wang Shao‐Bai Yan Prof. Dr. Wei‐Liang Duan 《Angewandte Chemie (International ed. in English)》2015,54(21):6265-6269
A palladium‐catalyzed enantioselective C? H arylation of N‐(o‐bromoaryl)‐diarylphosphinic amides is described for the synthesis of phosphorus compounds bearing a P‐stereogenic center. The method provides good enantioselectivities and high yields. The products were readily transformed into P‐chiral biphenyl monophosphine ligands. 相似文献
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《中国化学》2018,36(2):153-156
A series of structurally novel P‐chiral biaryl bisphosphorus ligands L1‐L5 (BABIBOPs) are developed, providing high efficiency for the first time in palladium‐catalyzed asymmetric hydrogenation of β‐aryl and β‐alkyl substituted β‐keto esters. With the Pd‐ L3 (iPr‐BABIBOP) catalyst, a series of chiral β‐hydroxyl carboxylic esters are formed in excellent enantioselectivities (up to>99% ee) and yields at catalyst loading as low as 0.01 mol%. 相似文献
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《化学:亚洲杂志》2017,12(24):3119-3122
A palladium‐catalyzed asymmetric redox‐relay Heck reaction of 4H ‐chromenes and arylboronic acids has been successfully developed. The reaction proceeded in moderate to good yields with good to high enantioselectivities. The resulting product is an advanced intermediate of bio‐active compound BW683C. 相似文献
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《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(1):174-184
Palladium‐catalyzed asymmetric allylic alkylation of nonstabilized ketone enolates to generate quaternary centers has been achieved in excellent yield and enantioselectivity. Optimized conditions consist of performing the reaction in the presence of two equivalents of LDA as base, one equivalent of trimethytin chloride as a Lewis acid, 1,2‐dimethoxyethane as the solvent, and a catalytic amount of a chiral palladium complex formed from π‐allyl palladium chloride dimer 3 and cyclohexyldiamine derived chiral ligand 4 . Linearly substituted, acyclic 1,3‐dialkyl substituted, and unsubstituted allylic carbonates function well as electrophiles. A variety of α‐tetralones, cyclohexanones, and cyclopentanones can be employed as nucleophiles. The absolute configuration generated is consistent with the current model in which steric factors control stereofacial differentiation. The quaternary substituted products available by this method are versatile substrates for further elaboration. 相似文献
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Yang‐Zi Liu Zhongao Wang Zesheng Huang Xing Zheng Wu‐Lin Yang Wei‐Ping Deng 《Angewandte Chemie (International ed. in English)》2020,59(3):1238-1242
The palladium‐catalyzed asymmetric [4+3] cyclization of trimethylenemethane donors with benzofuran‐derived azadienes furnishes chiral benzofuro[3,2‐b]azepine frameworks in high yields (up to 98 %) with exclusive regioselectivities and excellent stereoselectivities (up to >20:1 d.r., >99 % ee). This catalytic asymmetric [4+3] cyclization of Pd‐trimethylenemethane can enrich the arsenal of Pd‐TMM reactions in organic synthesis. In addition, this strategy provides an alternative approach to chiral azepines by a transition‐metal‐catalyzed asymmetric [4+3] cyclization. 相似文献