Interplay of the Ring and Steric Strains in the Highly Substituted Cyclopropanes

2021 ◽  
Author(s):  
Sergey L. Khursan ◽  
Ekaterina S. Akhmetshina
Keyword(s):  
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>

An Efficient Substrate-Induced Method for the Synthesis of CF3-Substituted Cyclopropanes by Metal-Free Reaction of Trifluoromethyl Styrylisoxazoles with Nitromethane

Synthesis ◽  
2020 ◽  
Author(s):  
Feng Li ◽  
Hai Ma ◽  
Qing-he Zhao ◽  
Guang-hao Yu ◽  
Ye-chen Meng ◽  
...  
Keyword(s):  
Functional Groups ◽  
Phase Transfer ◽  
Cyclization Reaction ◽  
Metal Free ◽  
Tert Butyl ◽  
Pharmacological Interest ◽  
Substituted Cyclopropanes

AbstractA series of (trifluoromethyl)cyclopropanes (TFCPs) tolerating a broad range of functional groups, known as tert-butyl bioisosteres, have been obtained from the cyclization reaction between nitromethane­ and 5-[β-(trifluoromethyl)styryl]isoxazoles in 70–94% yields and 75:25 to 90:10 dr. This method offers practical access to this cyclopropyl moiety of pharmacological interest, employing an inorganic base under phase-transfer conditions.

ChemInform Abstract: Novel Route to Triethylsilyl-Substituted Cyclopropanes.

ChemInform ◽  
2015 ◽  
Vol 46 (18) ◽  
pp. no-no
Author(s):  
Shi-Guang Li ◽  
Samir Z. Zard
Keyword(s):  
Substituted Cyclopropanes

ChemInform Abstract: MECHANISM-BASED INACTIVATION OF CYTOCHROME P-450 BY HETEROATOM-SUBSTITUTED CYCLOPROPANES AND FORMATION OF RING-OPENED PRODUCTS

1985 ◽  
Vol 16 (6) ◽  
Author(s):  
F. P. GUENGERICH ◽  
R. J. WILLARD ◽  
J. P. SHEA ◽  
L. E. RICHARDS ◽  
T. L. MACDONALD
Keyword(s):  
Cytochrome P 450 ◽  
Substituted Cyclopropanes

Frontispiece: Recent Progress Toward the Synthesis of Trifluoromethyl- and Difluoromethyl-Substituted Cyclopropanes

2017 ◽  
Vol 23 (21) ◽  
Author(s):  
Maxence Bos ◽  
Thomas Poisson ◽  
Xavier Pannecoucke ◽  
André B. Charette ◽  
Philippe Jubault
Keyword(s):  
Recent Progress ◽  
Substituted Cyclopropanes
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