دانلود رایگان مقاله لاتین سنتز کاتالیزور گوانیدین کایرال از سایت الزویر
عنوان فارسی مقاله:
سنتز کاتالیزور گوانیدین کایرال جدید و کاربرد آن در واکنش پیکتت-اسپنگلر نامتقارن
عنوان انگلیسی مقاله:
Synthesis of novel chiral guanidine catalyst and its application in the asymmetric Pictet-Spengler reaction
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Guanidine containing compounds have been used in various organic reactions as strong organic bases. Various chiral guanidine derivatives comprising from acyclic to polycyclic systems have been reported in the literature and have been used in a variety of asymmetric reactions e.g., Michael, Henry, Mannich, Strecker [1]. They activate the substrates by unique mode of dual hydrogen bonding thus providing high catalytic as well as high enantioselective activities. Several effective organocatalysts possessing the guanidinium functional group have been introduced to organic synthetic methodology. For example, chiral guanidine based on (R)-(+)-1-phenylethylamine was first developed by Nájera as the catalyst for asymmetric addition of nitroalkanes to aldehydes [2]. In the following years, many other scaffolds were introduced as effective and enantioselective chiral guanidine catalysts. These include Lipton's dipeptide guanidine [3] and Corey's bicyclic guanidine [4], useful for asymmetric Strecker reaction. Selected other chiral guanidine catalysts like Ishikawa's bifunctional guanidine [5,6], Terada's binaphthyl-based guanidine [7–9], and Tan's modified Corey-type bicyclic guanidine [10–15]. Finally, Dixon has developed a class of chiral bifunctional thiourea imininophosphoranes as effective catalysts for asymmetric nitro-Mannich reaction [16]. Also recently, Wang introduced a very effective tartrate-derived guanidine for diastereoselective Michael addition of 3-subtituted oxindoles to nitroolefins [17]. The introduction of an electron-withdrawing group attached to the guanidine moiety increases the acidity of the N\\H bonds thus allowing the construction of new effective organocatalysts acting as strong hydrogen bond donors [18]. Our idea was to develop a new chiral guanidine catalyst with the core skeleton easily accessible by the reaction of (R)-1-(1- phenylethyl)guanidine and aryl-substituted cyclopropenone. This type of reaction has already been reported in the literature [19] but neither its application to catalysis nor its chiral version was elaborated. We therefore expected that the reaction of (R)-1-(1-phenylethyl)guanidine with 2,3-diphenylcycloprop-2-enone would afford new chiral guanidine able to catalyze useful organic transformations. Herein, we report on the synthesis of such organocatalyst and its application in the asymmetric Pictet-Spengler reaction.
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کلمات کلیدی:
Synthesis of novel chiral guanidine catalyst and its ... - Journal Papers isi-dl.com/item/138767 Synthesis of novel chiral guanidine catalyst and its application in the asymmetric Pictet-Spengler reaction. sciencedirect.com ... A Novel Synthesis of Chiral Guanidinium Receptors and Their Use in ... pubs.acs.org/doi/abs/10.1021/jo7021026 by VD Jadhav - 2008 - Cited by 47 - Related articles Dec 28, 2007 - A novel synthetic route to the versatile chiral bicyclic guanidinium building block is described making use of l-methionine as a starting material ... Guanidines as Reagents and Catalysts I https://books.google.com/books?isbn=3319527258 Philipp Selig - 2017 - Science 3 Other Chiral Guanidines as Brønsted Base Catalysts The field of chiral ... 8) (for selected recent references on novel chiral guanidine catalysts, see [59–65]). Design and Synthesis of Novel Chiral Spiro Ionic Liquids - Organic ... pubs.acs.org/doi/abs/10.1021/ol052466y by ML Patil - 2006 - Cited by 54 - Related articles Dec 16, 2005 - Novel chiral imidazolium salts have been synthesized as examples of chiral ionic liquids with a spiro skeleton. Effects of N-substituents and ... Asymmetric Synthesis II: More Methods and Applications https://books.google.com/books?isbn=3527672591 Mathias Christmann, Stefan Bräse - 2013 - Science of. Novel. Axially. Chiral. Guanidine. Base. Catalysts. Chiral guanidine catalysts are attractive targets in organocatalysis, a research topic of increasing interest. Copper-Catalyzed Electrophilic Amination of sp2 and sp3 C−H Bonds https://books.google.com/books?isbn=3319388789 Stacey L. McDonald - 2016 - Science A catalytic approach to the synthesis of arylglycines. ... Ghosh S, Schneider C (2009) Enantioselective synthesis of a novel chiral 2,9-disubstituted 1 ... catalyzed by an axially chiral guanidine: acyclic keto esters react through an E enolate. [PDF]Development of Guanidine-Bisurea Bifunctional Organocatalysts with ... www.mdpi.com/1420-3049/20/7/12590/pdf by M Odagi - 2015 - Cited by 1 - Related articles Jul 10, 2015 - a novel type of guanidine-bisurea bifunctional catalysts (Figure 2) [12]. In the previous catalyst 2a, chiral spacers were synthesized from the ...
