A New Protocol for the In Situ Generation of Aromatic, Heteroaromatic, and Unsaturated Diazo Compounds and Its Application in Catalytic and Asymmetric Epoxidation of Carbonyl Compounds. Extensive Studies To Map Out Scope and Limitations, and Rationalization of Diastereo- and Enantioselectivities
作者:Varinder K. Aggarwal、Emma Alonso、Imhyuck Bae、George Hynd、Kevin M. Lydon、Matthew J. Palmer、Mamta Patel、Marina Porcelloni、Jeffery Richardson、Rachel A. Stenson、John R. Studley、Jean-Luc Vasse、Caroline L. Winn
DOI:10.1021/ja034606+
日期:2003.9.1
a general process for the in situ generation of diazo compounds from tosylhydrazone sodium salts has been established and applied in sulfur-ylide mediated epoxidation reactions. The chiral, camphor-derived, [2.2.1] bicyclic sulfide 7 was employed (at 5-20 mol % loading) to render the above processes asymmetric with a range of carbonyl compounds and tosylhydrazone sodium salts. Benzaldehyde tosylhydrazone
A novel method for the synthesis of α-amino alkenyl-substituted hydrazone derivatives was disclosed through silver-catalyzed reaction of sulfonyl hydrazones with ynamides. The present method features mild conditions, highstereoselectivity and good yields. The proposed mechanism involves silver-mediated generation of a keteniminium ion intermediate to facilitate the stereoselective addition of hydrazones
通过银催化磺酰与乙酰胺的反应,公开了一种合成α-氨基烯基取代的derivatives衍生物的新方法。本方法具有温和的条件,高的立体选择性和良好的收率。所提出的机理涉及银介导的酮亚胺离子中间体的产生,以促进在K 2 CO 3存在下立体选择性地添加,而在当前条件下不能构建吡唑环。
Hypervalent iodine (III)-mediated oxidation of aryl sulfonylhydrazones: A facile synthesis of N-aroyl-N′-acyl arylsulfonylhydrazides
作者:E. Ramakrishna、Kapil Dev、Saransh Wales Maurya、Ibadur Rahman Siddiqui、Rakesh Maurya
DOI:10.1016/j.tetlet.2016.12.085
日期:2017.2
We have developed a novel and efficient method for the oxidation of aryl sulfonylhydrazones to N-aroyl-N′-acyl arylsulfonylhydrazides, using hypervalentiodine (III) reagent in good yields at room temperature.
Transition Metal, Azide, and Oxidant-Free Homo- and Heterocoupling of Ambiphilic Tosylhydrazones to the Regioselective Triazoles and Pyrazoles
作者:Subhankar Panda、Pradip Maity、Debasis Manna
DOI:10.1021/acs.orglett.7b00313
日期:2017.4.7
cyclization reaction of two identical or different tosylhydrazones has been developed to access various 4,5-disubstituted-2H-triazoles under transition metal, azide, and oxidant-free conditions. A mechanistic rationalization study led to the identification of several electronically diverse unsaturated systems for regioselective synthesis of 1- and 2-substituted 1,2,3-triazoles and pyrazoles.
Diastereoselective Synthesis of Cyclopropane Amino Acids Using Diazo Compounds Generated in Situ
作者:Luke A. Adams、Varinder K. Aggarwal、Roger V. Bonnert、Bettina Bressel、Russell J. Cox、Jon Shepherd、Javier de Vicente、Magnus Walter、William G. Whittingham、Caroline L. Winn
DOI:10.1021/jo035060c
日期:2003.11.1
E selectivity, while reactions in the presence of meso-tetraphenylporphyrin iron chloride gave predominantly the corresponding Z isomers. The synthetic utility of this process was demonstrated in the synthesis of (+/-)-(Z)-2,3-methanophenylalanine [(+/-)-(Z)-1], the anti-Parkinson (+/-)-(E)-2,3-methano-m-tyrosine [(+/-)-(E)-2], and the natural product (+/-)-coronamic acid [(+/-)-3].