138101-00-5Relevant articles and documents
gem-Difluorocyclopropenes by [1+2] cycloaddition reactions between difluorocarbene and acetylenes having terminal or internal triple bonds
Bessard, Yves,Schlosser, Manfred
, p. 7323 - 7328 (1991)
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.
Monosubstituted 3,3-Difluorocyclopropenes as Bench-Stable Reagents: Scope and Limitations
Nosik, Pavel S.,Pashko, Mykola O.,Poturai, Andrii S.,Kvasha, Denys A.,Pashenko, Alexander E.,Rozhenko, Alexander B.,Suikov, Sergiy,Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.,Yagupolskii, Yurii L.
, p. 6604 - 6615 (2021/12/08)
A general approach to gem-difluorocyclopropenes synthesis based on the reaction of alkynes with Ruppert-Prakash reagent is reported. The proposed method is evaluated for the synthesis of a wide difluorocyclopropenes scope based on their bench lifespan and hydrolytic stability. The tolerance of the method for common functional groups was shown. Previously unavailable difluorocyclopropenes substituted with aliphatic were prepared using the proposed procedure. The retain of stability was proven by the multigram scale synthesis and further storage in the temperature interval ?78 to ?4 °C over a year. This makes them attractive building blocks and intermediates for organic synthesis. The reasons for dropping stability were defined. The relations between the structure of the substituents and the stability of the difluorocyclopropene ring were determined and discussed.
Enantioselective Functionalization of Difluorocyclopropenes Catalyzed by Chiral Copper Complexes: Proposal for Chiral gem-Dimethyl and tert-Butyl Analogues
Sekine, Keisuke,Ushiyama, Aina,Endo, Yu,Mikami, Koichi
, p. 7916 - 7924 (2020/07/16)
The highly enantioselective copper/chiral phosphine-catalyzed hydro-, bora-, and carbo-metalations of difluorocyclopropenes with PHMS [H-Si], H-BPin, (BPin)2, and (CH3)2Zn [Zn-Me] are shown to regiodivergently afford highly enantioenriched and functionalized difluorocyclopropanes. These examples can be viewed as the first successful syntheses of "chiral"gem-dimethyl and tert-butyl analogues.
Difluorocarbene Addition to Alkenes and Alkynes in Continuous Flow
Rullière, Pauline,Cyr, Patrick,Charette, André B.
supporting information, p. 1988 - 1991 (2016/06/01)
The first in-flow difluorocarbene generation and addition to alkenes and alkynes is reported. The application of continuous flow technology allowed for the controlled generation of difluorocarbene from TMSCF3 and a catalytic quantity of NaI. Th
METHOD OF PRODUCING DIFLUOROCYCLOPROPANE COMPOUNDS
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Paragraph 0039; 0040, (2016/12/26)
PROBLEM TO BE SOLVED: To provide a method of producing difluorocyclopropane compounds efficiently. SOLUTION: According to a method of this invention, a bis (trifluoromethyl) zinc DMPU complex that is represented by (CF3)2 Zn (DMPU)2 (1) (where DMPU shows N,N'-dimethyl propylene urea) and is stable at room temperature and useful as a reaction reagent, and olefins or acetylenes are reacted with each other, to obtain difluorocyclopropane compounds. COPYRIGHT: (C)2015,JPOandINPIT
Development of (Trifluoromethyl)zinc Reagent as Trifluoromethyl Anion and Difluorocarbene Sources
Aikawa, Kohsuke,Toya, Wataru,Nakamura, Yuzo,Mikami, Koichi
supporting information, p. 4996 - 4999 (2015/11/03)
The trifluoromethylation of carbonyl compounds is accomplished by the stable (trifluoromethyl)zinc reagent generated and then isolated from CF3I and ZnEt2, which can be utilized as a trifluoromethyl anion source (CF3-). The reaction proceeds smoothly with diamine as a ligand and ammonium salt as an initiator, providing the corresponding trifluoromethylated alcohol products. Moreover, the (trifluoromethyl)zinc reagent can also be employed as a difluorocarbene source (:CF2) not only for gem-difluoroolefination of carbonyl compounds with phosphine but also for gem-difluorocyclization of alkenes or alkynes via the thermal decomposition, respectively.
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 (2015/03/30)
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.
Modular, Concise, and Efficient Synthesis of Highly Functionalized 5-Fluoropyridazines by a [2 + 1]/[3 + 2]-Cycloaddition Sequence
Tran, Ga?l,Gomez Pardo, Domingo,Tsuchiya, Tomoki,Hillebrand, Stefan,Vors, Jean-Pierre,Cossy, Janine
supporting information, p. 3414 - 3417 (2015/07/28)
An easy access to 5-fluoropyridazines by a [2 + 1]/[3 + 2]-cycloaddition sequence between terminal alkynes, a difluorocarbene, and a diazo compound is reported. This approach does not necessitate the isolation of any intermediates, and a wide range of novel 5-fluoropyridazines was synthesized from readily available starting materials. Additionally, these compounds were used as a platform to access novel and highly diversified pyridazines.
Synthesis of gem-difluorocyclopropa(e)nes and O-, S-, N-, and P-difluoromethylated compounds with TMSCF2Br
Li, Lingchun,Wang, Fei,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 12390 - 12394 (2013/12/04)
Two-in-one: Me3SiCF2Br is an efficient difluorocarbene source and is compatible with both neutral and aqueous basic conditions. Bromide-ion-initiated [2+1] cycloaddition with alkenes/alkynes and hydroxide ion promoted α-addition with (thio)phenols, (thio)alcohols, sulfinates, heterocyclic amines, and H-phosphine oxides give the corresponding gem-difluorinated compounds with broad functional-group tolerance. Copyright
Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes
Wang, Fei,Zhang, Wei,Zhu, Jieming,Li, Huaifeng,Huang, Kuo-Wei,Hu, Jinbo
scheme or table, p. 2411 - 2413 (2011/04/15)
A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me3SiCF2Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively.
