36617-02-4Relevant academic research and scientific papers
Metal catalyzed carbonylation of gem-dibromocyclopropanes
Grushin,Alper
, p. 3349 - 3352 (1991)
The first examples of the catalytic carbonylation of gem-dibromocyclopropanes is described, using cobalt and nickel salts as catalysts under phase transfer conditions.
Versatile Synthesis of Cyclopropanecarboxylic Acid Derivatives by the Ni(CO)4-Induced Reductive Carbonylation Reaction of gem-Dibromocyclopropanes
Hirao, Toshikazu,Harano, Yoshiyuki,Yamana, Yoshihiro,Hamada, Yuji,Nagata, Shinichiro,Agawa, Toshio
, p. 1341 - 1348 (1986)
Reductive carbonylation of gem-dibromocyclopropanes was achieved by tetracarbonylnickel in the presence of alcohols, amines, thiols, or imidazole in DMF leading to the corresponding cyclopropanecarboxylic acid derivatives, respectively.Use of disulfides as an initial nucleophile resulted in carbonylation with sulfenylation at the geminal position.This method was applied to the intramolecular reductive carbonylation reaction of 2,2-dibromocyclopropanealkanols into bicyclic lactones.Nickel carbenoid and enolate complexes are assumed to be involved as key intermediates.
Stereoselective Functionalization of Racemic Cyclopropylzinc Reagents via Enantiodivergent Relay Coupling
An, Lun,Tong, Fei-Fei,Zhang, Shu,Zhang, Xingang
supporting information, p. 11884 - 11892 (2020/08/06)
Efficient construction of optically pure molecules from readily available starting materials in a simple manner is an ongoing goal in asymmetric synthesis. As a straightforward route, transition-metal-catalyzed enantioconvergent coupling between widely available secondary alkyl electrophiles and organometallic nucleophiles has emerged as a powerful strategy to construct chiral center(s). However, the scope of racemic secondary alkylmetallic nucleophiles for this coupling remains limited in specific substrates because of the difficulties in stereoselective formation of the key alkylmetal intermediates. Here, we report an enantiodivergent strategy to efficiently achieve an array of synthetically useful chiral cyclopropanes, including chiral fluoroalkylated cyclopropanes and enantiomerically enriched cyclopropanes with chiral side chains, from racemic cyclopropylzinc reagents. This strategy relies on a one-pot, two-step enantiodivergent relay coupling process of the racemic cis-cyclopropylzinc reagents with two different electrophiles, which involves kinetic resolution of racemic cis-cyclopropylzinc reagents through a nickel-catalyzed enantioselective coupling with alkyl electrophiles, followed by a stereospecific relay coupling of the remaining enantiomeric cyclopropylzinc reagent with various electrophiles, to produce two types of functionalized chiral cyclopropanes with opposite configurations on the cyclopropane ring. These chiral cyclopropanes are versatile synthons for diverse transformations, rendering this strategy effective for obtaining structurally diversified molecules of medicinal interest.
Some reactions of gem-dibromocyclopropanes and metal carbonyls
Lin, Shaw-Tao,Lee, Chuan-Chen,Ding, Mei-Fang,Liang, David W.,Jeng, An-Ting
scheme or table, p. 529 - 534 (2012/08/08)
A series of gem-dibromocyclopropanes were treated with various metal complexes. Among the metal complexes, Ru(CO)2(PPh3) 3, Ru(CO)3(PPh3)2, and Mo(CO) 6 were able to remove a bro
Preparation of arylspiro[2.4]hept-5-enes from aryldibromocyclopropanes via diallylation and metathesis reaction
Lin, Shaw-Tao,Lee, Chuan-Chen,Hu, Cheng-Kwan
, p. 591 - 592 (2007/10/03)
A series of arylspiro[2.4]hept-5-enes can be prepared from aryl-diallylcyclopropanes by using Grubbs' catalyst in good yields.
Bromine-magnesium exchange in gem-dibromocyclopropanes using Grignard reagents
Baird, Mark S,Nizovtsev, Alexey V,Bolesov, Ivan G
, p. 1581 - 1593 (2007/10/03)
Reaction of gem-dibromocyclopropanes with ethylmagnesium bromide at ambient temperature leads to very high yields of allenes; when cyclopropylidene-allene ring opening is suppressed, alternative carbenic products are observed, although other reactions compete. When the reactions are carried out at -60°C, a 1-bromo-1-(bromomagnesio)-cyclopropane is formed which may be trapped by a number of electrophiles.
Hydrodehalogenation of 1,1-dibromocyclopropanes by Grignard reagents promoted by titanium compounds
Dulayymi, Juma'a R. Al,Baird, Mark S.,Bolesov, Ivan G.,Nizovtsev, Alexey V.,Tverezovsky, Viacheslav V.
, p. 1603 - 1618 (2007/10/03)
1,1-Dibromocyclopropanes are converted into the corresponding monobromocyclopropanes (as mixtures of stereoisomers where appropriate) by reaction with 1.0-1.3 mol equiv. of ethylmagnesium bromide and 2-10 mol% titanium isopropoxide for 90%). With ethylmagnesium bromide, the reaction occurs very slowly in the absence of catalyst; with methylmagnesium bromide, the reaction does occur in the absence of catalyst, but is only slightly promoted in the presence of titanium isopropoxide. Reactions with a number of other Grignard reagents are also discussed. In the case of phenethylmagnesium bromide, the major product containing the phenethyl-group is ethylbenzene, together with small amounts of styrene and ethyl 4-phenyl-2-butyl ether, a product of trapping of the solvent, ether. In other cases, relatively large amounts of a diether, formally derived by hydrogen ion adjacent to the ether oxygen followed by dimerisation, are isolated. No products were identified incorporating the cyclopropane and either the Grignard alkyl group or the solvent. Labelling studies indicate that the hydrogen introduced into the cyclopropane is not derived from either the α- or β-positions of the Grignard reagent. When the reduction is carried out with phenethylmagnesium bromide in d8-tetrahydrofuran both monobromides contain deuterium.
The nickel and palladium catalyzed stereoselective cross coupling of cyclopropyl nucleophiles with aryl halides
De Lang,Brandsma
, p. 225 - 232 (2007/10/03)
The reaction of 2-phenylcyclopropylzinc chloride with some substituted (het)aryl halides gave the corresponding coupling products with good yields and stereoselectivities under the influence of a catalytic amount of Pd(PPh3)4. Other Ni- and Pd-catalysts were less efficient. Alkyl-substituted cyclopropyl nucleophiles gave lower yields.
Stereoselective Carbon-Carbon Bond-Forming Reaction of 1,1-Dibromocyclopropanes via 1-Halocyclopropylzincates
Harada, Toshiro,Katsuhira, Takeshi,Hattori, Kazuhiro,Oku, Akira
, p. 2958 - 2965 (2007/10/02)
Lithium trialkylzincates react efficiently with 1,1-dibromocyclopropanes 5 to give the corresponding alkylation products 7 nonstereoselectively.The reaction proceeds through a 1,2-alkyl migration of the intermediately formed zincate carbenoid 3 in an inve
Reduction and carbonylation of gem-dihalogeno cyclopropanes with iron pentacarbonyl
Reyne, F.,Brun, P.,Waegell, B.
, p. 4597 - 4600 (2007/10/02)
Reductive carbonylation of a gem-dibromo cyclopropane to carbomethoxycyclopropane can be achieved with excess Fe(CO)5 in DMF and an added nucleophile such as MeOH or MeONa.
