Sequence‐Dependent Stereodivergent Allylic Alkylation/Fluorination of Acyclic Ketones
作者:Xi‐Jia Liu、Shicheng Jin、Wen‐Yun Zhang、Qiang‐Qiang Liu、Chao Zheng、Shu‐Li You
DOI:10.1002/anie.201912882
日期:2020.1.27
The stereodivergent iridium-catalyzed allylicalkylation and fluorination of acyclicketones is described. α-Pyridyl-α-fluoroketones with vicinal tertiary and quaternary stereocenters were obtained in moderate to excellent yields and stereoselectivities. Distinct from known stereodivergent synthesis, for which two different chiral catalysts are required in general, herein we report a sequence-dependent
Stereodivergent Allylation of Azaaryl Acetamides and Acetates by Synergistic Iridium and Copper Catalysis
作者:Xingyu Jiang、Philip Boehm、John F. Hartwig
DOI:10.1021/jacs.7b12824
日期:2018.1.31
We report stereodivergent allylic substitution reactions of allylic esters with prochiral enolates derived from azaaryl acetamides and acetates to form products from addition of the enolates at the most substituted carbon of an allyl moiety with two catalysts, a chiral metallacyclic iridium complex and a chiral bisphosphine-ligated copper(I) complex, which individually control the configuration of
A One-Pot Palladium-Catalyzed Allylic Alkylation and Wittig Reaction of Phosphorus Ylides
作者:Wen-Bo Liu、Hu He、Li-Xin Dai、Shu-Li You
DOI:10.1002/chem.201000316
日期:2010.7.5
Put a(n) (y)lid(e) on it! The one‐pot palladium‐catalyzed allylic alkylation and Wittigreaction of phosphorus ylides with various aldehydes and ketenes has been realized, which produce skipped dienes, including trisubstituted alkenes and tetrasubstituted allenes, respectively (see scheme), in moderate to good overall yields.
Control of Diastereoselectivity for Iridium-Catalyzed Allylation of a Prochiral Nucleophile with a Phosphate Counterion
作者:Wenyong Chen、John F. Hartwig
DOI:10.1021/ja311363a
日期:2013.2.13
We report a highly diastereo- and enantioselective allylation of azlactones catalyzed by the combination of a metallacyclic iridium complex and an optically inactive phosphate anion. The process demonstrates an approach for conducting diastereoselective reactions with prochiralnucleophiles in the presence of metallacyclic allyliridium complexes. The reaction provides access to an array of enantioenriched
TBD catalysis with dimethyl carbonate: a fruitful and sustainable alliance
作者:Hatice Mutlu、Johal Ruiz、Susanne C. Solleder、Michael A. R. Meier
DOI:10.1039/c2gc35191a
日期:——
This work presents the synthesis of unsymmetric and symmetric organic carbonates as well as the synthesis of polycarbonates in an efficient and sustainable approach. All reactions were carried out at atmospheric pressure at 80 °C and the use of classic toxic and harmful chemicals, such as phosgene and carbon monoxide, was avoided. The key finding of this manuscript is that the use of 1,5,7-triazabicyclo[4.4.0]dec-5-ene, TBD, an organocatalyst, in combination with dimethyl carbonate (DMC), a non-toxic and renewable starting material, allows the synthesis of the mentioned unsymmetric carbonates in yields of up to 98% under optimized conditions. The structure of the alcohols used for this approach was found to influence the DMC–ROH ratio required to maximize the yield of the desired structure. Finally, the results obtained for the synthesis of low molecular weight building blocks could be transferred to the catalytic synthesis of high molecular weight polycarbonates.
这项研究以高效、可持续的方法合成了不对称和对称有机碳酸盐以及聚碳酸酯。所有反应都是在 80 °C 的常压下进行的,避免了使用传统的有毒有害化学品,如光气和一氧化碳。本手稿的主要发现是,使用 1,5,7-三氮杂双环[4.4.0]癸-5-烯(TBD,一种有机催化剂)与碳酸二甲酯(DMC,一种无毒且可再生的起始原料)相结合,可以在优化的条件下合成上述不对称碳酸盐,产率高达 98%。研究发现,这种方法所使用的醇的结构会影响 DMC-ROH 的比例,从而使所需结构的产率最大化。最后,合成低分子量结构单元的结果可用于催化合成高分子量聚碳酸酯。