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Cross‐Aldol Reaction of Isatin with Acetone Catalyzed by Leucinol: A Mechanistic Investigation 下载免费PDF全文
Dr. Mikhail A. Kabeshov Dr. Ondřej Kysilka Dr. Lubomír Rulíšek Dr. Yury V. Suleimanov Dr. Marco Bella Prof. Dr. Andrei V. Malkov Prof. Dr. Pavel Kočovský 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):12026-12033
Comprehensive mechanistic studies on the enantioselective aldol reaction between isatin ( 1 a ) and acetone, catalyzed by L ‐leucinol ( 3 a ), unraveled that isatin, apart from being a substrate, also plays an active catalytic role. Conversion of the intermediate oxazolidine 4 into the reactive syn‐enamine 6 , catalyzed by isatin, was identified as the rate‐determining step by both the calculations (ΔG≠=26.1 kcal mol?1 for the analogous L ‐alaninol, 3 b ) and the kinetic isotope effect (kH/kD=2.7 observed for the reaction using [D6]acetone). The subsequent reaction of the syn‐enamine 6 with isatin produces (S)‐ 2 a (calculated ΔG≠=11.6 kcal mol?1). The calculations suggest that the overall stereochemistry is controlled by two key events: 1) the isatin‐catalyzed formation of the syn‐enamine 6 , which is thermodynamically favored over its anti‐rotamer 7 by 2.3 kcal mol?1; and 2) the high preference of the syn‐enamine 6 to produce (S)‐ 2 a on reaction with isatin ( 1 a ) rather than its enantiomer (ΔΔG≠=2.6 kcal mol?1). 相似文献
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Inside Cover: Palladium/Zinc Co‐Catalyzed syn‐Stereoselectively Asymmetric Ring‐Opening Reaction of Oxabenzonorbornadienes with Phenols (Chem. Eur. J. 25/2015) 下载免费PDF全文
Sifeng Li Jianbin Xu Prof. Baomin Fan Zhiwu Lu Chaoyuan Zeng Prof. Zhaoxiang Bian Yongyun Zhou Prof. Jun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(25):8970-8970
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Inside Back Cover: Catalyst‐Dependent Selectivity in the Relay Catalytic Branching Cascade (Chem. Eur. J. 6/2015) 下载免费PDF全文
Avinash H. Bansode Aslam C. Shaikh Dr. Rahul D. Kavthe Shridhar Thorat Dr. Rajesh G. Gonnade Dr. Nitin T. Patil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2707-2707
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Inside Back Cover: Supramolecular Assembly of Poly(propyleneimine) Dendrimers Driven By Simple Monovalent Counterions (Chem. Eur. J. 51/2015) 下载免费PDF全文
Seyed Ali Eghtesadi Fadi Haso Marjan Alsadat Kashfipour Dr. Robert Scott Lillard Dr. Tianbo Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18863-18863
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Inside Back Cover: A Convenient Palladium‐Catalyzed Carbonylative Suzuki Coupling of Aryl Halides with Formic Acid as the Carbon Monoxide Source (Chem. Eur. J. 49/2015) 下载免费PDF全文
Dr. Xinxin Qi Li‐Bing Jiang Hao‐Peng Li Prof. Dr. Xiao‐Feng Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17987-17987
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Inside Back Cover: Control over Nanostructures and Associated Mesomorphic Properties of Doped Self‐Assembled Triarylamine Liquid Crystals (Chem. Eur. J. 5/2015) 下载免费PDF全文
Dr. Yuya Domoto Dr. Eric Busseron Prof. Dr. Mounir Maaloum Dr. Emilie Moulin Prof. Dr. Nicolas Giuseppone 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):2271-2271
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Inside Back Cover: The Active Sites of a Rod‐Shaped Hollandite DeNOx Catalyst (Chem. Eur. J. 27/2015) 下载免费PDF全文
Pingping Hu Dr. Manfred Erwin Schuster Dr. Zhiwei Huang Fei Xu Dr. Shifeng Jin Yaxin Chen Prof. Weiming Hua Prof. Dang Sheng Su Prof. Xingfu Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9915-9915
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Back Cover: Silver‐Catalyzed Cross‐Coupling of Propargylic Alcohols with Isocyanides: An Atom‐Economical Synthesis of 2,3‐Allenamides (Chem. Eur. J. 8/2014) 下载免费PDF全文
Jianquan Liu Zhenhua Liu Nannan Wu Dr. Peiqiu Liao Prof. Xihe Bi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(8):2388-2388
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Back Cover: Organomagnesium‐Catalyzed Isomerization of Terminal Alkynes to Allenes and Internal Alkynes (Chem. Eur. J. 22/2015) 下载免费PDF全文
Dr. Raphaël Rochat Koji Yamamoto Michael J. Lopez Haruki Nagae Dr. Hayato Tsurugi Prof. Dr. Kazushi Mashima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8300-8300