138101-05-0Relevant articles and documents
An efficient approach to gem-difluorocyclopropylstannanes via highly regio- and stereoselective hydrostannylation of gem-difluorocyclopropenes and their unique ring-opening reaction to afford β-fluoroallylic alcohols
Nihei,Hoshino,Konno
, p. 3721 - 3731 (2015)
Treatment of various gem-difluorocyclopropenes with 1.2 equiv. of n-Bu3SnH in the presence of 20 mol% of Et3B at 80 °C for 4 h led to the quantitative formation of the hydrostannylated products in a highly regio- and trans-selective manner. Additionally, the prepared trans-gem-difluorocyclopropylstannanes were treated with 1.5 equiv. of MeLi in THF at -78°C for 5 min, followed by quenching the reaction with various agents, such as H2O, alcohols, carboxylic acids, and tosylamide, to give the corresponding β-fluoroallylic alcohols, ethers, esters, and amides respectively with exclusive Z selectivity in acceptable yields.
Difluorocarbene Generation from TMSCF3: Kinetics and Mechanism of NaI-Mediated and Si-Induced Anionic Chain Reactions
García-Domínguez, Andrés,West, Thomas H.,Primozic, Johann J.,Grant, Katie M.,Johnston, Craig P.,Cumming, Grant G.,Leach, Andrew G.,Lloyd-Jones, Guy C.
, p. 14649 - 14663 (2020)
The mechanism of CF2 transfer from TMSCF3 (1), mediated by TBAT (2-12 mol %) or by NaI (5-20 mol %), has been investigated by in situ/stopped-flow 19F NMR spectroscopic analysis of the kinetics of alkene difluorocyclopropanation and competing TFE/c-C3F6/homologous perfluoroanion generation, 13C/2H KIEs, LFERs, CF2 transfer efficiency and selectivity, the effect of inhibitors, and density functional theory (DFT) calculations. The reactions evolve with profoundly different kinetics, undergoing autoinhibition (TBAT) or quasi-stochastic autoacceleration (NaI) and cogenerating perfluoroalkene side products. An overarching mechanism involving direct and indirect fluoride transfer from a CF3 anionoid to TMSCF3 (1) has been elucidated. It allows rationalization of why the NaI-mediated process is more effective for less-reactive alkenes and alkynes, why a large excess of TMSCF3 (1) is required in all cases, and why slow-addition protocols can be of benefit. Issues relating to exothermicity, toxicity, and scale-up are also noted.
A Cyclopropenethione-Phosphine Ligation for Rapid Biomolecule Labeling
Row, R. David,Prescher, Jennifer A.
, p. 5614 - 5617 (2018/09/25)
Cyclopropenethiones are reported as new bioorthogonal reagents. These motifs react readily with substituted phosphines to provide thiocarbonyl adducts. In some cases, the ligations are >300-fold faster than analogous reactions with bioorthogonal cyclopropenones. Dialkyl cyclopropenethiones are also stable in aqueous buffers and can be used for biomolecule labeling in vitro and in cell lysate. The rapid reactivity and biocompatibility of cyclopropenethiones suggest that they will be useful probes for cellular studies.
gem-Difluorocyclopropenes by [1+2] cycloaddition reactions between difluorocarbene and acetylenes having terminal or internal triple bonds
Bessard, Yves,Schlosser, Manfred
, p. 7323 - 7328 (2007/10/02)
Difluorocarbene, generated by the Burton method, i.e. by the dissociation of (triphenylphosphonio)difluoromethanide, was found to add to terminal or internal acetylenes with astonishing ease. Actually, it reacts roughly 10 times faster with 4-octyne than with cis-4-octene. The gem-difluorocyclopropenes resulting from the [1+2] cycloaddition process can be isolated with good to excellent yields. They are perfectly stable under anhydrous conditions while in aqueous media they are quantitatively converted to cyclopropenones. - Unsubstituted olefinic ring positions rapidly undergo a base catalyzed hydrogen/deuterium exchange. The acidity of such 2-alkyl- or 2-aryl-1,1-difluorocyclopropenes is estimated to be higher than that of terminal acetylenes.
