29667-51-4Relevant academic research and scientific papers
Hydrodehalogenation of alkyl halides catalyzed by a trichloroniobium complex with a redox active α-diimine ligand
Nishiyama, Haruka,Hosoya, Hiromu,Parker, Bernard F.,Arnold, John,Tsurugi, Hayato,Mashima, Kazushi
, p. 7247 - 7250 (2019)
A high-valent d0 niobium(v) complex, (α-diimine)NbCl3 (1), bearing a dianionic redox-active α-diimine ligand served as a catalyst for a hydrodehalogenation reaction of alkyl halides in the presence of PhSiH3. During the catalytic reaction, the redox-active α-diimine ligand allowed the complex to reversibly release and accept one-electron through switching its coordination mode between a dianionic folded form and a monoanionic planar one.
Stereoselective Functionalization of Racemic Cyclopropylzinc Reagents via Enantiodivergent Relay Coupling
An, Lun,Tong, Fei-Fei,Zhang, Shu,Zhang, Xingang
, 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.
Olefin cyclopropanations via sequential atom transfer radical addition-dechlorination reactions
Thommes, Katrin,Severin, Kay
scheme or table, p. 188 - 190 (2011/07/07)
In organic synthesis, cyclopropanation reactions are often performed with Simmons-Smith-type reagents or by transition metal catalyzed reactions of olefins with diazo compounds. A novel method for the synthesis of substituted cyclopropanes is described that is based on a two-step reaction sequence. Olefins are reacted with 1,1'-dichlorides in a Ru-catalyzed atom transfer radical addition (ATRA) process and the resulting 1,3-dichlorides are directly converted into cyclopropanes by reductive coupling with magnesium. This one-pot procedure is applicable to a variety of substrates and can be performed in an inter- or intramolecular fashion. Schweizerische Chemische Gesellschaft.
Olefin cyclopropanation by a sequential atom-transfer radical addition and dechlorination in the presence of a ruthenium catalyst
Thommes, Katrin,Kiefer, Gregor,Scopelliti, Rosario,Severin, Kay
supporting information; experimental part, p. 8115 - 8119 (2010/01/16)
Without diazo: The reductive coupling of olefins with dichloro compounds in the presence of a ruthenium catalyst and magnesium gives cyclopropanes in good yield (see scheme).
Reductive Carbonylation of gem-Dihalogenocyclopropanes by Pentacarbonyliron(0) in the Presence of Sodium Methoxide
Reyne, Francoise,Waegell, Bernard,Brun, Pierre
, p. 1162 - 1167 (2007/10/02)
The reaction of gem-dihalogenocyclopropanes derivatives with (tetracarbonyl)(methoxycarbonylato)ferrate(I-) has been investigated; gem-dibromocyclopropanes and gem-chlorobromocyclopropane derivatives are reduced and carbonylated.It could be shown that a bromo ester such as methyl 1-bromo-2-phenylcyclopropanecarboxylate is an intermediate in the transformation of 1,1-dibromo-2-phenylcyclopropane into methyl cis- and trans-2-phenylcyclopropanecarboxylates and dimethyl 2-phenyl-1,1-cyclopropanedicarboxylate.
REDUCTION OF GEM-DICHLOROCYCLOPROPANES BY HYDRAZINE HYDRATE IN THE PRESENCE OF RANEY NICKEL
Molchanov, A. P.,Kalyamin, S. A.,Kostikov, R. R.
, p. 1366 - 1368 (2007/10/03)
The reduction of gem-dichlorocyclopropane compounds with hydrazine hydrate in the presence of Raney nickel in alcohols takes place selectively with the formation of monochlorocyclopropanes. he ratio of the E and Z isomers depends on the structure of the initial dichloride.
Reduction of Organic Halides with Diethyl Phosphonate and Triethylamine
Hirao, Toshikazu,Kohno, Shuichiro,Ohshiro, Yoshiki,Agawa, Toshio
, p. 1881 - 1882 (2007/10/02)
Reduction of organic halides with diethyl phosphonate and triethylamine is surveyed.
