Synthesis of Trifluoromethyl‐Substituted Cyclopropanes via Inorganic Base‐Mediated Cycloaddition Reactions

2019 ◽  
Vol 8 (11) ◽  
pp. 2054-2057 ◽  
Author(s):  
Huijuan Zhu ◽  
Shuangshuang Liu ◽  
Chunnian He ◽  
Jing Zhang ◽  
Lei Wang
Keyword(s):  
Cycloaddition Reactions ◽  
Substituted Cyclopropanes

[2 + 1] Cycloaddition Reactions of a 1-Seleno-2-silylethene to 2-Sulfonylacrylates:  Stereoselective Synthesis of Sulfone-Substituted Cyclopropanes

1999 ◽  
Vol 64 (26) ◽  
pp. 9521-9528 ◽  
Author(s):  
Shoko Yamazaki ◽  
Yuichiro Yanase ◽  
Etsuko Tanigawa ◽  
Shinichi Yamabe ◽  
Hatsue Tamura
Keyword(s):  
Stereoselective Synthesis ◽  
Cycloaddition Reactions ◽  
Substituted Cyclopropanes

Three-Component [1+1+1] Cyclopropanation with Ruthenium(II)

2018 ◽  
Author(s):  
Tanner C. Jankins ◽  
Robert R. Fayzullin ◽  
Eugene Khaskin
Keyword(s):  
Quaternary Carbon ◽  
Poor Control ◽  
One Step ◽  
Synthetic Routes ◽  
Mechanistic Investigations ◽  
Chiral Centers ◽  
Metal Catalyzed ◽  
The Right ◽  
Substituted Cyclopropanes

We report a one-step, Ru(II)-catalyzed cyclopropanation reaction that is conceptually different from the previously reported protocols that include Corey-Chaykovsky, Simmons-Smith, and metal catalyzed carbene attack on olefins. Under the current protocol, various alcohols are transformed into sulfone substituted cyclopropanes with excellent isolated yields and diastereoselectivities. This new reaction forms highly congested cyclopropane products with three new C–C bonds, three or two new chiral centers and one new quaternary carbon center. 22 examples of isolated substrates are given. Previously reported synthetic routes for similar substrates are all multi-step, linear routes that proceed with overall low yields and poor control of stereochemistry. Experimental mechanistic investigations suggest initial metal-catalyzed dehydrogenation of the alcohol substrate and catalyst independent stepwise attack of two equivalents of sulfone on the aldehyde under basic conditions. While the Ru(II) is only responsible for the initial dehydrogenation step, the rate of aldehyde formation is crucial to maintaining the right balance of intermediates needed to afford the cyclopropane product.

Enantioselective Multi-Component Cyclopropane Synthesis Enabled by Cu-Catalyzed Cyclopropene Carbometallation with Organoboron Reagent

2018 ◽  
Author(s):  
Zhanyu Li ◽  
Mengru Zhang ◽  
Yu Zhang ◽  
Shuang Liu ◽  
Jinbo Zhao ◽  
...  
Keyword(s):  
Carbon Source ◽  
Stereoselective Synthesis ◽  
Organometallic Reagents ◽  
Preliminary Results ◽  
Quaternary Center ◽  
Chiral Centers ◽  
Substituted Cyclopropanes ◽  
Proof Of Principle

Deployment of organoboron in lieu of the strongly basic <br>organometallic reagents as carbon source in Cu-catalyzed <br>cyclopropene carbometallation opens unprecedented three-<br>component reactivity for stereoselective synthesis of poly-substituted cyclopropanes. A proof-of-principle demonstration of this novel carbometallation strategy is presented herein for a highly convergent access to poly-substituted aminocyclopropane framework via <br>carboamination. Preliminary results on asymmetric desymmetrization with commercial bisphosphine ligands attained high levels of enantioselection, offering a straightforward access to enantioenriched aminocyclopropanes bearing all-three chiral centers, including an all-carbon quaternary center. This strategy may underpin a host of novel synthetic protocols for poly-substituted cyclopropanes. <br>

Multicomponent 1,3-Dipolar Cycloaddition Reactions in the Construction of Hybrid Spiroheterocycles

2013 ◽  
Vol 17 (18) ◽  
pp. 1929-1956 ◽  
Author(s):  
Natarajan Arumugam ◽  
Raju Kumar ◽  
Abdulrahman Almansour ◽  
Subbu Perumal
Keyword(s):  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions
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