New developments in radical chemistry. Applications to total synthesis and asymmetric processes

2000 ◽  
Vol 72 (9) ◽  
pp. 1605-1613 ◽  
Author(s):  
Christophe Aïssa ◽  
Bénédicte Delouvrié ◽  
Anne-Lise Dhimane ◽  
Louis Fensterbank ◽  
Max Malacria

This article reviews our contribution in the field of radical synthetic chemistry, focusing on cascades relying on the use of propargylic BMDMS ethers and asymmetric synthesis using enantiopure vinylsulfoxides.

Synlett ◽  
2018 ◽  
Vol 29 (16) ◽  
pp. 2108-2116 ◽  
Author(s):  
Louis Fensterbank ◽  
Marion Barbazanges

This Account surveys almost two decades of methodological developments and their straightforward applications to the total synthesis of simple natural products. The main directions covered include radical chemistry and cascades, electrophilic catalysis based on coinage metals, and asymmetric synthesis based on bis(sulfoxides) auxiliaries.1 Introduction2 Radical Cascades2.1 N-Cyanamides2.2 Homolytic Substitution at Sulfur Atom to Give Sultines3 Electrophilic Catalysis Based on Platinum(II) and Gold(I) Complexes4 From Alkylydene Bis(sulfoxides) to Chiral Carboxylic Acids5 Conclusion and Perspectives


ChemInform ◽  
2010 ◽  
Vol 32 (23) ◽  
pp. no-no
Author(s):  
Christophe Aissa ◽  
Benedicte Delouvrie ◽  
Anne-Lise Dhimane ◽  
Louis Fensterbank ◽  
Max Malacria

2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>


2014 ◽  
Vol 10 ◽  
pp. 1228-1232 ◽  
Author(s):  
Jens Schmidt ◽  
Zeinab Khalil ◽  
Robert J Capon ◽  
Christian B W Stark

The heronapyrroles A–C have first been isolated from a marine-derived Streptomyces sp. (CMB-0423) in 2010. Structurally, these natural products feature an unusual nitropyrrole system to which a partially oxidized farnesyl chain is attached. The varying degree of oxidation of the sesquiterpenyl subunit in heronapyrroles A–C provoked the hypothesis that there might exist other hitherto unidentified metabolites. On biosynthetic grounds a mono-tetrahydrofuran-diol named heronapyrrole D appeared a possible candidate. We here describe a short asymmetric synthesis of heronapyrrole D, its detection in cultivations of CMB-0423 and finally the evaluation of its antibacterial activity. We thus demonstrate that biosynthetic considerations and the joint effort of synthetic and natural product chemists can result in the identification of new members of a rare class of natural products.


2006 ◽  
Vol 1 (10) ◽  
pp. 1934578X0600101 ◽  
Author(s):  
Vijay Nair ◽  
Rajeev S. Menon ◽  
Sreekumar Vellalath

Ever since its isolation in 1820, Quinine has played a crucial role in the development of organic chemistry, the chemical industry and modern medicine. A total synthesis of quinine, widely regarded as an event of epochal importance, was claimed by Woodward and Doering in 1945. This work, however, heavily relied on unsubstantiated literature reports and it appears that Woodward's work fell short of a total synthesis of quinine. The first total synthesis of quinine was reported by Uskokovic in the 1970s. The first stereoselective total synthesis of quinine was accomplished only in 2001, by Stork, who incidentally is the originator of the concept of stereoselectivity in total synthesis. Apart from the stereoselectivity, Stork's synthesis of quinine is remarkable for its conceptual uniqueness and retrosynthetic novelty. Naturally, this work has been attested as a landmark in organic synthesis by leaders in the field. Subsequently, Jacobson and Kobayashi reported the catalytic asymmetric synthesis of quinine in 2003 and 2004, respectively. Both these synthesis have followed a similar approach. The present review has attempted to provide a concise account of the synthesis of quinine from a historical perspective.


Synlett ◽  
2004 ◽  
Vol 2004 (15) ◽  
pp. 2689-2692 ◽  
Author(s):  
Dieter Schinzer ◽  
Claudia Schulz ◽  
Olga Krug

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