Carboxylic Acids as A Traceless Activation Group for Conjugate Additions: A Three-Step Synthesis of (±)-Pregabalin
作者:Lingling Chu、Chisa Ohta、Zhiwei Zuo、David W. C. MacMillan
DOI:10.1021/ja505964r
日期:2014.8.6
carboxylic acids as a traceless activation group for radical Michael additions has been accomplished via visible light-mediated photoredox catalysis. Photon-induced oxidation of a broad series of carboxylic acids, including hydrocarbon-substituted, α-oxy, and α-amino acids, provides a versatile CO2-extrusion platform to generate Michael donors without the requirement for organometallic activation or propagation
羧酸作为自由基迈克尔加成的无痕活化基团的直接应用是通过可见光介导的光氧化还原催化实现的。光子诱导氧化一系列广泛的羧酸,包括碳氢化合物取代的、α-氧基和 α-氨基酸,提供了一个多功能的 CO2 挤出平台来生成迈克尔供体,而无需有机金属活化或传播。多种迈克尔受体适用于这种新的共轭加成策略。还介绍了该技术在药物普瑞巴林(由辉瑞以商品名 Lyrica 商业化)的三步合成中的应用。
Enantioselective Formal Hydration of α,β-Unsaturated Imides by Al-Catalyzed Conjugate Addition of Oxime Nucleophiles
作者:Christopher D. Vanderwal、Eric N. Jacobsen
DOI:10.1021/ja045563f
日期:2004.11.1
(salen)Al-catalyzed asymmetric conjugate addition of salicylaldoxime to α,β-unsaturated imides is the key step in an efficient and highly enantioselective two-step formal hydration of these electron-deficient olefins. This reaction constitutes the first example of an enantioselective conjugate addition of an oxygen-centered nucleophile to α,β-unsaturated carboxylic acid derivatives. Application of this method
Directed γ-C(sp<sup>3</sup>)–H Alkylation of Carboxylic Acid Derivatives through Visible Light Photoredox Catalysis
作者:Dian-Feng Chen、John C. K. Chu、Tomislav Rovis
DOI:10.1021/jacs.7b09306
日期:2017.10.25
Visible light photoredox catalysis enables direct γ- C(sp3)-H alkylation of saturated aliphatic carbonyl compounds. Electron-deficient alkenes are used as the coupling partners in this reaction. Distinguished site selectivity is controlled by the predominant 1,5-hydrogen atom transfer of an amidyl radical generated in situ.
Elucidating the Mechanism of the Asymmetric Aza-Michael Reaction
作者:Pim Huat Phua、Suju P. Mathew、Andrew J. P. White、Johannes G. de Vries、Donna G. Blackmond、King Kuok (Mimi) Hii
DOI:10.1002/chem.200601706
日期:2007.5.25
chelate ring with the metal centre; coordinating through the 1,3-dicarbonyl moiety. Isotopic labelling revealed that the addition of N-H occurs in a highly stereoselective manner, allowing the synthesis of opticallyactive beta(2)- and beta(2,3)-amino acid derivatives. The stereochemistry of the addition is postulated to be syn. In situ kinetic studies provided evidence for product inhibition. The binding
One-Carbon Oxidative Annulations of 1,3-Enynes by Catalytic C−H Functionalization and 1,4-Rhodium(III) Migration
作者:Johnathon D. Dooley、Hon Wai Lam
DOI:10.1002/chem.201706043
日期:2018.3.15
Rhodium(III)‐catalyzed C−H functionalization‐oxidativeannulations of aromatic substrates with 1,3‐enynes that contain allylic hydrogen atoms cis to the alkyne are described. The key step in these reactions is an alkenyl‐to‐allyl 1,4‐rhodium(III) migration to give electrophilic π‐allylrhodium(III) species. Nucleophilic trapping of these species gives heterocycles such as benzopyrans, isobenzofuranones