共查询到20条相似文献,搜索用时 15 毫秒
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Beau P. Pritchett Jun Kikuchi Yoshitaka Numajiri Brian M. Stoltz 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(43):13727-13730
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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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(39):11959-11963
The first asymmetric synthesis of important α,α‐disubstituted N‐alkyl allyl amine scaffolds through allylic substitution is reported. This approach is based on palladium catalysis and features ample scope with respect to both the allylic precursor and amine reagent, and high asymmetric induction with enantiomeric ratios (e.r.) up to 98.5:1.5. The use of less‐reactive anilines is also feasible, providing enantioenriched α,α‐disubstituted N‐aryl allylic amines. 相似文献
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Yeshua Sempere Jan L. Alfke Simon L. Rssler Erick M. Carreira 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(28):9637-9641
Morpholine ketene aminal is employed in iridium‐catalyzed asymmetric allylic alkylation reactions as a surrogate for amide enolates to prepare γ,δ‐unsaturated β‐substituted morpholine amides. Kinetic resolution or, alternatively, stereospecific substitution affords the corresponding products in high enantiomeric excess. The utility of the products generated by this method has been showcased by their further elaboration into amines, ketones, or acyl silanes. A putative catalytic intermediate (η3‐allyl)iridium(III) with achiral P,Olefin‐ligand was synthetized and characterized for the first time. 相似文献
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Fang Gao Yunmi Lee Kyoko Mandai Amir H. Hoveyda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2010,122(45):8548-8552
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Barry M. Trost Johnathan E. Schultz Yu Bai 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(34):11946-11951
We describe the development of a Pd‐catalyzed decarboxylative asymmetric allylic alkylation of α‐nitro allyl esters to afford acyclic tetrasubstituted nitroalkanes. Optimization of the reaction parameters revealed unique ligand and solvent combinations crucial for achieving chemo‐ and enantioselective C‐alkylation of electronically challenging benzylic nitronates and sterically encumbered 2‐allyl esters. Substrates were efficiently accessed in a combinatorial fashion by a cross‐Claisen/ α‐arylation sequence. The method provides functional group orthogonality that complements nucleophilic imine allylation strategies for α‐tertiary amine synthesis. 相似文献
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Carina I. Jette Irina Geibel Shoshana Bachman Masaki Hayashi Shunya Sakurai Hideki Shimizu Jeremy B. Morgan Brian M. Stoltz 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(13):4341-4345
Herein, we report the first Pd‐catalyzed enantioselective arylation of α‐substituted γ‐lactams. Two sets of conditions were developed for this transformation, allowing for the use of either aryl chlorides or bromides as electrophiles. Utilizing a highly electron‐rich dialkylphosphine ligand we have been able to construct α‐quaternary centers in good yields (up to 91 % yield) and high enantioselectivities (up to 97 % ee). 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(38):11660-11663
Herein, we report a zirconium‐catalyzed enantio‐ and diastereoselective inter/intramolecular double carboalumination of unactivated 2‐substituted 1,5‐dienes, which provides efficient and direct access to chiral cyclopentanes through the generation of two stereocenters, including one all‐carbon quaternary stereocenter, generally with excellent diastereo‐ and high enantioselectivity. This tandem carboalumination process creates two new C−C bonds as well as one C−Al bond, which can be oxidized in situ with O2 or hydrolyzed. Furthermore, the obtained chiral cyclopentanes can be readily functionalized to provide various chiral compounds. 相似文献
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