5801-17-2Relevant academic research and scientific papers
Boron tribromide as a reagent for anti-Markovnikov addition of HBr to cyclopropanes
Chen, Shuming,Gieuw, Matthew H.,Houk, K. N.,Ke, Zhihai,Yeung, Ying-Yeung
, p. 9426 - 9433 (2020/10/02)
Although radical formation from a trialkylborane is well documented, the analogous reaction mode is unknown for trihaloboranes. We have discovered the generation of bromine radicals from boron tribromide and simple proton sources, such as water ortert-butanol, under open-flask conditions. Cyclopropanes bearing a variety of substituents were hydro- and deuterio-brominated to furnish anti-Markovnikov products in a highly regioselective fashion. NMR mechanistic studies and DFT calculations point to a radical pathway instead of the conventional ionic mechanism expected for BBr3
Base-catalysed reductive relay hydroboration of allylic alcohols with pinacolborane to form alkylboronic esters
Wang, Zi-Chao,Shen, Di,Gao, Jian,Jia, Xian,Xu, Youjun,Shi, Shi-Liang
, p. 8848 - 8851 (2019/08/01)
An unprecedented base-catalysed reductive relay hydroboration of allylic alcohols is described. Commercially available nBuLi was found to be a robust transition metal-free initiator for this protocol, affording various boronic esters in high yield and selectivity. Mechanistically, this methodology involves a one-pot three-step successive process (dehydrocoupling/allylic hydride substitution/anti-Markovnikov hydroboration).
Intrazeolite photooxygenation of chiral alkenes. Control of facial selectivity by confinement and cation-π interactions
Stratakis, Manolis,Raptis, Christos,Sofikiti, Nikoletta,Tsangarakis, Constantinos,Kosmas, Giannis,Zaravinos, Ioannis-Panagiotis,Kalaitzakis, Dimitris,Stavroulakis, Dimitris,Baskakis, Constantinos,Stathoulopoulou, Aggeliki
, p. 10623 - 10632 (2007/10/03)
Depending on the nature of the substituents on the stereogenic carbon atom, the ene reaction of singlet oxygen with several chiral alkenes by confinement within thionin-supported zeolite NaY, may exhibit significant changes on facial selectivity by comparison to their photooxygenation reaction in solution. It is proposed that, apart from the conformational consequences as a result of the alkene confinement within the zeolite cavities, a synergism between Na+-π interactions and singlet oxygen-Na+ interactions plays a significant role in the transition states of ene hydroperoxidation. Within NaY, the diastereoselectivity may significantly depend on the site selectivity, as probed through specific deuterium labelling of trisubstituted alkenes bearing a gem-dimethyl group. In certain cases, a remote stereogenic centre relative to the reacting double bond may induce enhanced diastereoselection and regioselectivity.
Saturated heterocyclic carboxamide derivatives
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, (2008/06/13)
A saturated heterocyclic carboxamide derivative of the following general formula (I) and salts thereof which have platelet activating factor (PAF) antagonizing activity. STR1
Ene Reaction Mechanisms. 1. Chirality Transfer to the Enophile 4-Methyl-N-sulfinylbenzenesulfonamide
Bussas, Reinhard,Muensterer, Heribert,Kresze, Guenter
, p. 2828 - 2832 (2007/10/02)
The ene reaction of (S)-(+)-3-phenyl-1-butene (1) with N-sulfinyl-p-toluenesulfonamide (2) leads to the optically active (E)-2-alkenesulfinamide 3.This corresponds to a chirality transfer from the chiral carbon center in 1 to the sulfur atom of the produc
ZUR BILDUNGSWEISE VON 1-PHENYLPROPYLLITHIUM AUS BENZYLLITHIUM UND ETHYLEN IN TETRAHYDROFURAN
Maercker, Adalbert,Stoetzel, Reinhard
, p. 1 - 12 (2007/10/02)
3-Phenylpropyllithium primarily formed by the addition of benzyllithium to ethylene in THF does not undergo an intramolecular 1,3-proton shift to 1-phenylpropyllithium.Fast protonation by the solvent takes place instead, yielding n-propylbenzene and new ethylene.An equilibrium is then established between n-propylbenzene and additional benzyllithium, with the formation of toluene and 1-phenylpropyllithium; the equilibrium, however, strongly favours the starting materials (K293=1.1*10-4).As, on the other hand, 1-phenylpropyllithium reacts with ethylene much more rapidly than does benzyllithium, it is removed from the equilibrium and mainly branched secondary products are still obtained.
Organofluorosilicates in Organic Synthesis. XVI. Synthesis of Organopentafluorosilicates via the Diels-Alder, Ene, and Friedel-Crafts Reaction. Their Transformations to Organic Halides and Alcohols
Tamao, Kohei,Yoshida, Jun-ichi,Akita, Munetaka,Sugihara, Yoshihiro,Iwahara, Takahisa,Kumada, Makoto
, p. 255 - 260 (2007/10/02)
Described herein are several representative examples of cleavage reactions of otherwise hardly accessible organopentafluorosilicates which are obtainable via the Diels-Alder reaction, ene reaction, and the Friedel-Crafts reaction of vinyl-, ethynyl-, or allyl-trichlorosilanes.The Diels-Alder reaction between vinyltrichlorosilane and o-xylylene generated in situ by debromination of α,α'-dibromo-o-xylene afforded (1,2,3,4-tetrahydro-2-naphthyl)-trichlorosilane which was converted to the corresponding silicate.The silicate reacted with NBS and MCPBA to give the respective bromide and alcohol.The Diels-Alder reaction between ethynyltrichlorosilane and methyl coumalate gave a mixture of meta and para isomers of methyl (trichlorosilyl)benzoate in the ratio of 55/45, the silicate of which reacted with NBS to give two positional isomers of methyl bromobenzoate.The electronic effect of the methoxycarbonyl group on the Si-C bond cleavage was small.The silicate derived from 4-octenyltrichlorosilane which was obtained by the ene reaction between vinyltrichlorosilane and 1-hexene afforded, upon treatment with NBS, 4-octenyl bromide in the ratio of E/Z=83/17.The sterically crowded neophylsilicate obtainable via the Friedel-Crafts reaction of 2-methyl-1-propenyltrichlorosilane with benzene underwent the cleavage reaction with NBS in methanol.Neophyl bromide was formed with CuBr2 in a low yield, no product being formed arising from rearrangement of the neophyl radical.
