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Dr. Qing‐Qing Cheng Lynée A. Massey Brook S. Willett Dr. Yongming Deng Dr. Hadi Arman Prof. Dr. Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2018,57(32):10343-10346
Enoldiazoimides, a new subclass of enoldiazo compounds, generate enol‐substituted carbonyl ylides whose reactions with sulfur ylides enable an unprecedented formal [4+2] cycloaddition. The resulting multifunctionalized indolizidinones, which incorporate sulfur, are formed in good yields under mild reaction conditions. The uniqueness of this transformation stems from the role of the silyl‐protected enol, since the corresponding acetyldiazoimide failed to provide any cross‐products in metal‐catalyzed reactions with sulfur ylides. This copper‐catalyzed cycloaddition is initiated with the generation of enol‐substituted carbonyl ylides and sulfur ylides from enoldiazoimides and sulfonium salts, respectively, and proceeds through stepwise six‐membered ring formation, C?O and C?S bond cleavage, and silyl and acetyl group migration. 相似文献
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《中国化学》2018,36(5):421-429
Reported herein is an example of highly regio‐, diastereo‐ and enantioselective Cu(I)‐catalyzed intermolecular [3+2] cycloaddition reaction of α‐substituted iminoesters with α‐trifluoromethyl α,β‐unsaturated esters. This novel strategy provided a facile access to pyrrolidines with two skipped (aza)quaternary stereocenters including a CF3 all‐carbon quaternary stereocenter. A broad substrate scope was observed and high yields (up to 94%) with excellent diastereoselectivity (up to >20 : 1 d.r.) and enantioselectivity (up to 98% ee) were obtained. 相似文献
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Fuyuhiko Inagaki Dr. Syu Narita Takuma Hasegawa Shinji Kitagaki Dr. Chisato Mukai Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(11):2007-2011
No templates needed : The title reaction makes it easy to construct the bicyclo[6.3.0]undecadienone framework in high yields (see scheme). A template effect is not required to achieve this ring‐closing reaction efficiently. The present method can be applied to the construction of bicyclo[5.3.0] and bicyclo[4.3.0] ring systems. Ts=p‐toluenesulfonyl.
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Reversal of the Regiochemistry in the Rhodium‐Catalyzed [4+3] Cycloaddition between Vinyldiazoacetates and Dienes 下载免费PDF全文
Dr. Pablo E. Guzmán Dr. Yajing Lian Prof. Dr. Huw M. L. Davies 《Angewandte Chemie (International ed. in English)》2014,53(48):13083-13087
A regio‐, diastereo‐, and enantioselective [4+3] cycloaddition between vinylcarbenes and dienes has been achieved using the dirhodium tetracarboxylate catalyst [Rh2(S‐BTPCP)4]. This methodology provides facile access to 1,4‐cycloheptadienes that are regioisomers of those formed from the tandem cyclopropanation/Cope rearrangement reaction of vinylcarbenes with dienes. 相似文献
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Rhodium Enalcarbenoids: Direct Synthesis of Indoles by Rhodium(II)‐Catalyzed [4+2] Benzannulation of Pyrroles 下载免费PDF全文
Sudam Ganpat Dawande Vinaykumar Kanchupalli Jagadeesh Kalepu Haribabu Chennamsetti Bapurao Sudam Lad Dr. Sreenivas Katukojvala 《Angewandte Chemie (International ed. in English)》2014,53(16):4076-4080
Disclosed herein is the design of an unprecedented electrophilic rhodium enalcarbenoid which results from rhodium(II)‐catalyzed decomposition of a new class of enaldiazo compounds. The synthetic utility of these enalcarbenoids has been successfully demonstrated in the first transition‐metal‐catalyzed [4+2] benzannulation of pyrroles, thus leading to substituted indoles. The new benzannulation has been applied to the efficient synthesis of the natural product leiocarpone as well as a potent adipocyte fatty‐acid binding protein inhibitor. 相似文献
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Catalytic Asymmetric Synthesis of Cyclopentyl β‐Amino Esters by [3+2] Cycloaddition of Enecarbamates with Electrophilic Metalloenolcarbene Intermediates 下载免费PDF全文
Dr. Yongming Deng Matthew V. Yglesias Dr. Hadi Arman Prof. Dr. Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2016,55(34):10108-10112
Chiral cyclopentyl β‐amino esters are formed catalytically by [3+2] cycloaddition reactions of enecarbamates with electrophilic metalloenolcarbenes in high yield with up to 98 % ee and excellent diastereocontrol. Use of β‐silyl‐substituted enoldiazoacetates with a chiral dirhodium catalyst and trans‐β‐arylvinylcarbamates are optimal for this transformation, which occurs with hydrogen‐bond association between the vinylcarbamate and the intermediate metalloenolcarbene. Reductive conversion of the protected amino esters forms highly functionalized cyclopentyl β‐amino acids and 3‐aminocyclopentanones. 相似文献
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Murielle Keller Dr. Abdelkarim Sani Souna Sido Patrick Pale Prof. Dr. Jean Sommer Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2810-2817
Clicking in zeolites : Copper(I)‐exchanged zeolites proved to be practical and efficient catalysts for the cycloaddition of azomethine imines with alkynes, providing a convenient access to N,N‐bicyclic pyrazolidinone derivatives (see scheme). With high regioselectivity, 100 % atom economy, and convenient product isolation, this heterogeneously catalyzed version of the Dorn cycloaddition corresponds to click‐chemistry criteria.
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Diastereo‐ and Enantioselective Copper(I)‐Catalyzed Intermolecular [3+2] Cycloaddition of Azomethine Ylides with β‐Trifluoromethyl β,β‐Disubstituted Enones 下载免费PDF全文
Zhan‐Ming Zhang Bing Xu Shan Xu Prof. Dr. Hai‐Hong Wu Prof. Dr. Junliang Zhang 《Angewandte Chemie (International ed. in English)》2016,55(21):6324-6328
Reported herein is an asymmetric [3+2] cycloaddition reaction of azomethine ylides with β‐trifluoromethyl β,β‐disubstituted enones, a reaction which is enabled by a Ming‐Phos‐derived copper(I) catalyst (Ming‐Phos=chiral sulfinamide monophosphines, Figure 2 ). This method provides scalable and efficient access to the highly substituted pyrrolidines with a trifluoromethylated, all‐carbon quaternary stereocenter in good yields with up to greater than 20:1 d.r. and 98 % ee. The reaction has a broad substrate scope and tolerates a wide range of functional groups. 相似文献
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Rebecca L. Grange Dr. Michael J. Gallen Dr. Heiko Schill Dr. Jenny P. Johns Lin Dong Dr. Peter G. Parsons Dr. Paul W. Reddell Dr. Victoria A. Gordon Dr. Paul V. Bernhardt Dr. Craig M. Williams Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(29):8894-8903
A detailed examination of [4+2] cycloaddition reactions between 1,8‐disubstituted cyclooctatetraenes and diazo compounds revealed that 4‐phenyl‐1,2,4‐triazole‐3,5‐dione (PTAD) reacts to form either 2,3‐ or 3,4‐disubstituted adducts. The product distribution can be controlled by modulating the electron density of the cyclooctatetraene. Unprecedented [4+2] cycloadditions between diisopropyl azodicarboxylate (DIAD) and 1,8‐disubstituted cyclooctatetraenes are also described and further manipulation of a resulting cycloadduct uncovered a new pathway to the synthetically challenging bicyclo[4.2.0]octa‐2,4‐diene family. Variation of the substituents resulted in a range of compounds displaying selective action against different human tumour cell types. 相似文献
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Copper Salt‐Controlled Divergent Reactivity of [Cu]CF2PO(OEt)2 with α‐Diazocarbonyl Derivatives 下载免费PDF全文
Dr. Tatiana Besset Prof. Dr. Xavier Pannecoucke Dr. Thomas Poisson 《Angewandte Chemie (International ed. in English)》2016,55(45):14141-14145
Herein, we report a copper salt‐controlled divergent reactivity toward α‐diazocarbonyl compounds. By a simple change of the copper counteranion under identical reaction conditions, the reported method allowed an easy access to either (Z)‐α‐fluorovinylphosphonate or alkyl‐SCF2PO(OEt)2 derivatives in good yields. Mechanistic studies were performed and suggested two different pathways to explain the formation of these products. 相似文献
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Zhuo Xin Dr. Søren Kramer Dr. Jacob Overgaard Prof. Dr. Troels Skrydstrup 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(26):7926-7930
A new synthetic route to the privileged 1,2‐dihydroisoquinolines is reported. This method, which relies on a gold‐catalyzed formal [4+2] cycloaddition between ynamides and imines, provides a new retrosynthetic disconnection of the 1,2‐dihydroisoquinoline core by installing the 1,8a C?C and 2,3 C?N bonds in one step. Both aldimines and ketimines can be used as substrates. In addition, one example of dihydrofuropyridine synthesis is also demonstrated. 相似文献
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Copper(I)‐Catalyzed Alkylation of Polyfluoroarenes through Direct CH Bond Functionalization 下载免费PDF全文
Shuai Xu Guojiao Wu Fei Ye Xi Wang Huan Li Xia Zhao Dr. Yan Zhang Prof. Dr. Jianbo Wang 《Angewandte Chemie (International ed. in English)》2015,54(15):4669-4672
The copper(I)‐catalyzed alkylation of electron‐deficient polyfluoroarenes with N‐tosylhydrazones and diazo compounds has been developed. This reaction uses readily available starting materials and is operationally simple, thus representing a practical method for the construction of C(sp2)? C(sp3) bonds with polyfluoroarenes through direct C? H bond functionalization. Mechanistically, copper(I) carbene formation and subsequent migratory insertion are proposed as the key steps in the reaction pathway. 相似文献