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Dr. Yongming Deng Lynée A. Massey Dr. Peter Y. Zavalij Prof. Dr. Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2017,56(26):7479-7483
The first asymmetric [3+1]-cycloaddition was successfully achieved by copper(I) triflate/double-sidearmed bisoxazoline complex catalyzed reactions of β-triisopropylsilyl-substituted enoldiazo compounds with sulfur ylides. This methodology delivered a series of chiral cyclobutenes in good yields with high enantio- and diastereoselectivities (up to 99 % ee, and >20:1 d.r.). Additionally, the [3+1]-cycloaddition of catalytically generated metallo-enolcarbenes was successfully extended to reaction with a stable benzylidene dichlororuthenium complex. 相似文献
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Stereoselective Synthesis of Tetrahydroindolizines through the Catalytic Formation of Pyridinium Ylides from Diazo Compounds 下载免费PDF全文
Dr. Jonathan Day Dr. Ben McKeever‐Abbas Dr. James Dowden 《Angewandte Chemie (International ed. in English)》2016,55(19):5809-5813
Commercially available iron(III) and copper(I) complexes catalyzed multicomponent cycloaddition reactions between diazo compounds, pyridines, and electrophilic alkenes to give alkaloid‐inspired tetrahydroindolizidines in high yield with high diastereoselectivity. Hitherto, the catalytic formation of versatile pyridinium ylides from metal carbenes has been poorly developed; the broad utility demonstrated herein sets the stage for the invention of further multicomponent reactions in future. 相似文献
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Varinder K. Aggarwal Alison Thompson Ray V.H. Jones Mike C.H. Standen 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):361-362
Abstract: This paper describes a new method for the preparation of aziridines from imines and diazocompounds which requires catalytic amounts of metal salts and sulfides and operates under neutral conditions. Using enantiomerically pure sulfides, high enantioselectivity has been achieved in the aziridination process. 相似文献
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Toshihiko Sone Gang Lu Shigeki Matsunaga Dr. Masakatsu Shibasaki Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(9):1677-1680
Better the second time around : The title compounds were synthesized by using a one‐pot double methylene transfer catalyzed by a heterobimetallic La/Li complex. Chiral amplification in the second step was the key to obtaining oxetanes in high enantiomeric excess (see scheme).
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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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Dr. Valentín Hornillos Dr. Carlos Vila Dr. Edwin Otten Prof. Dr. Ben L. Feringa 《Angewandte Chemie (International ed. in English)》2015,54(27):7867-7871
The first catalytic enantioselective synthesis of ambiphilic phosphine boronate esters is presented. The asymmetric boration of α,β‐unsaturated phosphine oxides catalyzed by a copper bisphosphine complex affords optically active organoboronate esters that bear a vicinal phosphine oxide group in good yields and high enantiomeric excess. The synthetic utility of the products is demonstrated through stereospecific transformations into multifunctional optically active compounds. 相似文献
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Catalytic Enantioselective [5+2] Cycloaddition between Oxidopyrylium Ylides and Enals under Dienamine Activation 下载免费PDF全文
Ane Orue Dr. Uxue Uria Prof. Efraim Reyes Prof. Luisa Carrillo Prof. Jose L. Vicario 《Angewandte Chemie (International ed. in English)》2015,54(10):3043-3046
Benzopyrylium ylides generated in situ from 1‐acetoxyisochroman‐4‐ones reacted with α,β‐unsaturated aldehydes in the presence of a bifunctional secondary‐amine/squaramide catalyst to furnish [5+2] cycloaddition products in good yield with high diastereo‐ and enantioselectivity. The reaction proceeds by dienamine activation and involves β,γ‐functionalization of the enal. The dienamine intermediates showed exclusive β,γ‐reactivity and provided direct access to compounds with the 8‐oxabicyclo[3.2.1]octane framework. The ability of the bifunctional secondary‐amine/squaramide catalyst to engage in hydrogen‐bonding interactions with the ylide made it particularly effective in terms of both the yield and the stereoselectivity of the transformation. 相似文献