scholarly journals Amine-Catalyzed Decarboxylative Aldol Reaction of β-Ketocarboxylic Acids with Trifluoropyruvates

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2773
Author(s):  
Ryouta Kawanishi ◽  
Shinya Hattori ◽  
Seiji Iwasa ◽  
Kazutaka Shibatomi

Decarboxylative aldol reaction of aliphatic carboxylic acids is a useful method for C–C bond formation because carboxylic acids are an easily available class of compounds. In this study, we found that the decarboxylative aldol reaction of tertiary β-ketocarboxylic acids and trifluoropyruvates proceeded smoothly to yield the corresponding aldol products in high yields and with high diastereoselectivity in the presence of a tertiary amine catalyst. In this reaction, we efficiently constructed a quaternary carbon center and an adjacent trifluoromethylated carbon center. This protocol was also extended to an enantioselective reaction with a chiral amine catalyst, and the desired product was obtained with up to 73% enantioselectivity.

Synthesis ◽  
2017 ◽  
Vol 49 (24) ◽  
pp. 5263-5284 ◽  
Author(s):  
Hongli Bao ◽  
Yajun Li ◽  
Liang Ge ◽  
Munira Muhammad

Radical decarboxylation has emerged as an attractive method for the formation of C–C bonds starting from easily accessible carboxylic acids. In this review, we attempt to bring the readers up to date in this rapidly expanding field. Specifically, we will cover recent advances in Csp3–C bond formation via the radical decarboxylation of aliphatic carboxylic acids and their activated forms, such as N-hydroxyphthalimide esters (NHP esters), alkyl diacyl peroxides, alkyl peresters, and aryliodine(III) dicarboxylates. The scope and limitation of these transformations will be discussed, highlighting gaps in knowledge and research and examining the mechanisms underlying radical decarboxylation. We aim to make this review a stepping stone for further development in this field.1 Introduction2 Aliphatic Carboxylic Acids3 N-Hydroxyphthalimide Esters (NHP Esters)4 Alkyl Diacyl Peroxides5 Alkyl Peresters6 Aryliodine(III) Dicarboxylates7 Conclusion


Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 1-29
Author(s):  
Yahu A Liu ◽  
Xuebin Liao ◽  
Hui Chen

AbstractAliphatic carboxylic acids are abundant in natural and synthetic sources and are widely used as connection points in many chemical transformations. Radical decarboxylative functionalization promoted by transition-metal catalysis has achieved great success, enabling carboxylic acids to be easily transformed into a wide variety of products. Herein, we highlight the recent advances made on transition-metal (Ni, Cu, Fe, Co or Cr) catalyzed C–X (X = C, N, H, O, B, or Si) bond formation as well as syntheses of ketones, amino acids, alcohols, ethers and difluoromethyl derivatives via radical decarboxylation of carboxylic acids or their derivatives, including, among others, redox-active esters (RAEs), anhydrides, and diacyl peroxides.1 Introduction2 Ni-Catalyzed Decarboxylative Functionalizations3 Cu-Catalyzed Decarboxylative Functionalizations4 Fe-Catalyzed Decarboxylative Functionalizations5 Co- and Cr-Catalyzed Decarboxylative Functionalizations6 Conclusions


RSC Advances ◽  
2015 ◽  
Vol 5 (65) ◽  
pp. 53155-53160 ◽  
Author(s):  
Oliver Kreye ◽  
Michael A. R. Meier

Phenyl esters were obtained in moderate to high yields by reaction of aliphatic and aromatic carboxylic acids with one equivalent of diphenyl carbonate in the presence of catalytic amounts of tertiary amine bases, under neat conditions at elevated temperatures (>100 °C).


2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.


2018 ◽  
Vol 21 (4) ◽  
pp. 298-301 ◽  
Author(s):  
Ghasem Marandi

Aim and Objective: The reaction of cyclohexylisocyanide and 2-aminopyridine-3- carboxylic acid in the presence of benzaldehyde derivatives in ethanol led to 3-(cyclohexylamino)-2- arylimidazo[1,2-a]pyridine-8-carboxylic acids in high yields. In a three component condensation reaction, isocyanide reacts with 2-aminopyridine-3-carboxylic acid and aromatic aldehydes without any prior activation. Material and Methods: The synthesized products have stable structures which have been characterized by IR, 1H, 13C and Mass spectroscopy as well as CHN-O analysis. Results: In continuation of our attempts to develop simple one-pot routes for the synthesis of 3- (cyclohexylamino)-2-arylimidazo[1,2-a]pyridine-8-carboxylic acids, aromatic aldehydes with divers substituted show a high performance. Conclusion: In conclusion, this study introduces the art of combinatorial chemistry using a simple one-pot procedure for the synthesis of new materials which are interesting compounds in medicinal and biological sciences.


2003 ◽  
Vol 73 (11) ◽  
pp. 1792-1798 ◽  
Author(s):  
F. P. Maguna ◽  
M. B. Ninez ◽  
N. B. Okulik ◽  
E. A. Castro

2013 ◽  
Vol 54 (32) ◽  
pp. 4324-4326 ◽  
Author(s):  
Yasuharu Yoshimi ◽  
Sonoka Washida ◽  
Yoshiki Okita ◽  
Keisuke Nishikawa ◽  
Kousuke Maeda ◽  
...  

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