23525-05-5Relevant academic research and scientific papers
Nickel-Catalyzed Conversion of Enol Triflates into Alkenyl Halides
Hofstra, Julie L.,Poremba, Kelsey E.,Shimozono, Alex M.,Reisman, Sarah E.
supporting information, p. 14901 - 14905 (2019/11/11)
A Ni-catalyzed halogenation of enol triflates was developed and it enables the synthesis of a broad range of alkenyl iodides, bromides, and chlorides under mild reaction conditions. The reaction utilizes inexpensive, bench-stable Ni(OAc)2?4 H2O as a precatalyst and proceeds at room temperature in the presence of sub-stoichiometric Zn and either 1,5-cyclooctadiene or 4-(N,N-dimethylamino)pyridine.
Ruthenium-catalyzed transformation of aryl and alkenyl triflates to halides
Imazaki, Yusuke,Shirakawa, Eiji,Ueno, Ryota,Hayashi, Tamio
supporting information, p. 14760 - 14763 (2012/11/07)
Aryl triflates were transformed to aryl bromides/iodides simply by treating them with LiBr/NaI and [Cp*Ru(MeCN)3]OTf. The ruthenium complex also catalyzed the transformation of alkenyl sulfonates and phosphates to alkenyl halides under mild conditions. Aryl and alkenyl triflates undergo oxidative addition to a ruthenium(II) complex to form η'1- arylruthenium and 1-ruthenacyclopropene intermediates, respectively, which are transformed to the corresponding halides.
STEREOSELECTIVE SYNTHESIS OF CIS-4-METHYLSPHINGOSINE AND DERIVATIVES THEREOF
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Page/Page column 18-19, (2012/11/14)
The invention provides for synthesis of a (S-R) dihydroxy-amino-methylalkylene characterized by the general formula I, or its R-S diastereomer, wherein R1 is CH2OH or CH2-CH2OH, and R2 is C2 to C20 al
A mild synthesis of vinyl halides and gem-dihalides using triphenyl phosphite-halogen-based reagents
Spaggiari, Alberto,Vaccari, Daniele,Davoli, Paolo,Torre, Giovanni,Prati, Fabio
, p. 2216 - 2219 (2007/10/03)
A new application of (PhO)3P-halogen-based reagents to the synthesis of vinyl halides and gem-dihalides is described. Vinyl halides were prepared in good to excellent yields from enolizable ketones, whereas aldehydes afforded the corresponding gem-dihalides. The halogenation proceeded smoothly under mild conditions.
Reactions of cyclohexenyl iodonium tetrafluoroborate with bromide ion: Retardation due to the formation of λ3-bromoiodane
Okuyama, Tadashi,Imamura, Shohei,Fujita, Morifumi
, p. 1609 - 1613 (2007/10/03)
The reaction of 4-tert-butylcyclohex-1-enyl(phenyl)iodonium tetrafluoroborate (1a) and the 4-chlorophenyl derivative (1b) with bromide ion was examined in methanol, acetonitrile, and chloroform. Products include those derived from the intermediate cyclohexenyl cation as well as 1-bromocyclohexene. Kinetic measurements show that the reaction of 1 is strongly retarded by the added bromide. The curved dependence of the observed rate constant on the bromide concentration is typical of a pre-equilibrium formation of the intermediate adduct with a fast bromide-independent reaction (solvolysis of the iodonium ion). The formation of the adduct, λ3-bromoiodane, was also confirmed by the UV spectral change. The relative reactivity of the iodonium ion and λ3-bromoiodane is evaluated to be on the order of 102. The bromide substitution product forms both via the SN1 reaction of the free iodonium ion and via the ligand coupling of the iodane.
REACTIONS OF VINYLSILANES WITH LEWIS ACID-ACTIVATED IODOSYLBENZENE: STEREOSPECIFIC SYNTHESIS OF VINYLIODONIUM TETRAFLUOROBORATES AND THEIR REACTIONS AS HIGHLY ACTIVATED VINYL HALIDES
Ochiai, Masahito,Sumi, Kenzo,Takaoka, Yoshikazu,Kunishima, Munetaka,Nagao, Yoshimitsu,et al.
, p. 4095 - 4112 (2007/10/02)
Alkenyl(phenyl)iodonium tetrafluoroborates 3 were synthesized from alkenylsilanes 1 by the reaction with iodosylbenzene and boron trifluoride-diethyl ether or triethyloxonium tetrafluoroborate.The reaction proceeds stereospecifically with retention of configuration of 1.X-ray diffraction analysis of (4-tert-butylcyclohexenyl)phenyliodonium tetrafluoroborate (3b) revealed the highly ionic structure with the distorted T-shape arrangement.Iodonium salts 3 behave like the highly activated species of vinyl iodides due to the high leaving ability of the iodine(III) substituents.Thus, a variety of substituted olefins including α-cyano and α-nitro olefins, vinyl sulfides, vinyl halides and α,β-unsaturated esters, were synthesized from 3 under mild conditions.A ligand coupling mechanism via the formation of 10-I-3 intermediate 27 containing a copper(III) ligand is proposed for the substitutions of 3 with nucleophiles.
Halogenative Deoxygenation of Ketones; Vinyl Bromides and/or gem-Dibromides by Cleavage of 1,3-Benzodioxoles (Ketone Phenylene Acetals) with Boron Tribromide
Napolitano, Elio,Fiaschi, Rita,Mastrorilli, Ettore
, p. 122 - 125 (2007/10/02)
Representative ketones 1 have been converted in generally good yields to the respective 1,3-benzodioxoles 5 by trans-acetalization of ketone dimethyl acetals with 1,2-dihydroxybenzene, and cleaved with boron tribromide. 1,3-Benzodioxoles derived from α-unbranched aliphatic ketones gave in general a mixture of vinyl bromides and gem-dibromides; pure gem-dibromides could be selectively obtained in most of cases using a suitable reaction time. 1,3-Benzodioxoles derived from α-branched ketones gave complex mixtures and their cleavage appears to be of little synthetic signifance. 1,3-Benzodioxoles of aromatic ketones gave vinyl bromides only.Aliphatic cyclic gem-dibromides 3 were converted to the respective vinyl bromides 2 by phase-transfer-catalysed dehydrobromination.
INTRAMOLECULAR ALKYLATION OF VINYLGERMANES AND IODODEGERMYLATION OF 1-CYCLOALKENYLGERMANES
Oda, Hiroji,Oshima, Koichiro,Nozaki, Hitosi
, p. 53 - 56 (2007/10/02)
Whereas 2-methyl-2,3-epoxy-6-triethylgermyl-6-tridecene gave the expected alkylidenecyclopentanol upon treatment with TiCl4, 5-triethylgermyl-5-dodecenal dimethyl acetal provided the unexpected cyclohexene derivative.Transformation of 1-tri-ethylgermylcyc
VINYLIODONIUM SALTS: THEIR STEREOSPECIFIC SYNTHESIS AND REACTIONS AS THE ACTIVATED VINYL HALIDES
Ochiai, Masahito,Sumi, Kenzo,Nagao, Yoshimitsu,Fujita, Eiichi
, p. 2351 - 2354 (2007/10/02)
Vinyliodonium salts 2 were synthesized from vinylsilanes 1 by the reaction with iodosylbenzene and triethyloxonium tetrafluoroborate.The reaction occurs stereospecifically with retention of configuration.Vinyliodonium salts 2 are highly effective as the activated species of vinyl iodides.Thus, a variety of substituted olefins including α-cyano and α-nitro olefins, vinyl sulfides, vinyl halides, and α,β-unsaturated esters, were prepared from 2 under mild reaction conditions.
