Metal-Free Addition of Boronic Acids to Silylnitronates

Synlett ◽  
2020 ◽  
Vol 31 (09) ◽  
pp. 856-860
Author(s):  
Laurent El Kaïm ◽  
Mansour Dolé Kerim ◽  
Pakoupati Boyode ◽  
Julian Garrec

We report for the first time a metal-free addition of boronic acids to silylnitronates to afford oxime derivatives through aryl transfer on the carbon nitrogen double bond. A reaction mechanism has been proposed in relation with a DFT study on the key aryl transfer. This arylation process is effective for cycloalkenyl nitro derivatives leading to oximes that may be oxidatively converted into 3-arylisoxazole derivatives.

2016 ◽  
Vol 12 ◽  
pp. 2614-2619 ◽  
Author(s):  
Riccardo Porta ◽  
Alessandra Puglisi ◽  
Giacomo Colombo ◽  
Sergio Rossi ◽  
Maurizio Benaglia

The metal-free reduction of nitro compounds to amines mediated by trichlorosilane was successfully performed for the first time under continuous-flow conditions. Aromatic as well as aliphatic nitro derivatives were converted to the corresponding primary amines in high yields and very short reaction times with no need for purification. The methodology was also extended to the synthesis of two synthetically relevant intermediates (precursors of baclofen and boscalid).


2018 ◽  
Vol 5 (13) ◽  
pp. 2065-2072 ◽  
Author(s):  
Yang Wang ◽  
Shou-Ren Zhang ◽  
Yanyan Wang ◽  
Ling-Bo Qu ◽  
Donghui Wei

A DFT study of the NHC-catalyzed cascade Michael/aldol/lactamization reaction has been performed for the first time.


2020 ◽  
Vol 16 (5) ◽  
pp. 606-610
Author(s):  
Nguyen T. Diep ◽  
Luu D. Huy

Background: Vietnam currently imports up to 90% of the pharmaceuticals it consumes and 100% of the steroid-based pharmaceuticals. The ability for efficient chemical synthesis of the steroids could create commercial opportunities to address this issue. Synthesis of 21-acetoxypregna-1,4,9(11)- triene-17α,21-diol-3,20-dione is considered a key intermediate in the scheme of steroidal drug synthesis. Previous synthesis attempts of such steroids (corticoids) introduce a double bond at C-1(2) in the final stage of synthesis, which delivers a poor yield and reduces the economic efficiency of the process. Objective: To study and develop a novel and effective method for the synthesis of 21-acetoxypregna- 1,4,9(11)-triene-17α,21-diol-3,20-dione. Methods: Using 9α-hydroxyandrostenedione as a substrate chemical synthesis was performed as follows: pregnane side chain construction at C-17 (acetylene method), introduction of C-1(2) double bond (using SeO2), epimerization of C-17 (via 17-ONO2 ester) and Stork’s iodination. Results: 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione was prepared from 9α- hydroxyandrostenedione with an improved yield compared to previous attempts. Conclusion: Here, 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione has been synthesized from 9α-hydroxyandrostenedione based on a novel, effective and commercially feasible scheme. The introduction of the C-1(2) double bond at an earlier stage of the synthesis has increased the economic efficiency of the entire process. For the first time, the indirect epimerization mechanism has been clarified along with the configuration of the C-17 stereo-center which has been confirmed using NOESY data.


RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18246-18251
Author(s):  
Selçuk Eşsiz

A computational study of metal-free cyanomethylation and cyclization of aryl alkynoates with acetonitrile is carried out employing density functional theory and high-level coupled-cluster methods, such as [CCSD(T)].


1962 ◽  
Vol 3 (26) ◽  
pp. 1269-1274 ◽  
Author(s):  
D.Y. Curtin ◽  
C.G. McCarty

Author(s):  
Changfeng Huang ◽  
Jijing Hu ◽  
Guangxian Chen ◽  
Minjian Wu ◽  
Hua Cao ◽  
...  

A sustainable, environmentally benign electrochemical oxidative three-component cyclization of allylic alcohols, boronic acids, and dichalcogenides under metal-free and oxidant-free conditions has been developed, which provides an efficient manner for the...


2021 ◽  
Author(s):  
Kai Ji ◽  
Ka Lu ◽  
Jie Huang ◽  
Zi-Hao Li ◽  
Tong-Mei Ding ◽  
...  

A highly regio- and diastereo-selective Brønsted acid-catalyzed tandem hydrothiolation/Friedel-Crafts reaction of linear 1,3-dienes has been developed for the first time, which provides a metal-free, atom-economic and concise way of constructing...


2006 ◽  
Vol 110 (10) ◽  
pp. 3552-3558 ◽  
Author(s):  
Xian-Yang Chen ◽  
Yi-Xin Zhao ◽  
Shu-Guang Wang

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