89657-20-5Relevant academic research and scientific papers
Carbocyclic cis-[1.1.1]-tris-σ-homobenzenes - Syntheses by triple epoxide → cyclopropane conversions, structural data, [σ2s+σ2s+σ2s] cycloreversions
Ruecker, Christoph,Mueller-Boetticher, Hermann,Braschwitz, Wolf-Dieter,Prinzbach, Horst,Reifenstahl, Uwe,Irngartinger, Hermann
, p. 967 - 989 (2007/10/03)
By triple epoxide → cyclopropane transformation starting from cis-benzene trioxide the 3α,6α,9α-tris(TIPS-ethynyl) (1b), -tris(alkoxycarbonyl) (1d, e), -tricyano (1f), and -tris(ammoniomethyl) (1j) derivatives of the still elusive parent cis-[1.1.1]-tris-σ-homobenzene (1a) have been synthesized. Out of a number of carbon nucleophiles tested, a weakly basic mixed cyanocuprate of Li-TIPS-propyne proved the reagent of choice: Eliminations were largely avoided, the scyllo[*]-2,4,6-tris(TIPS-propargyl)cyclohexane-1,3,5-triol (13a), obtained in a stereoselective one-pot threefold epoxide opening (up to 69%), allowed the pertinent functional group manipulations. The selectivity of the base-induced triple cyclopropane ring closure in the flexible cyclohexane precursors strongly depends on the activating groups and is promoted by fixation of the "all-axial" conformation as an adamantoid orthophosphate. The ΔG≠ values determined for the generally neat 3σ → 3π isomerizations [28.5 (1e), 29.0 (1f), 22.6 (1j) kcal mol-1] are in line with concerted reaction courses ([σ2s+σ2s+σ2s]). For the trinitrile 1f an X-ray structure analysis confirmed a nearly planar cyclohexane ring and a relatively large cyclohexane/cyclopropane interplanary angle (113°). VCH Verlagsgesellschaft mbH, 1997.
1-METHOXY-1-(PHENYLTHIO)CYCLOPROPANES FROM OLEFINS VIA THE PUMMERER REARRANGEMENT
Bhupathy, M.,Cohen, Theodore
, p. 4797 - 4800 (2007/10/02)
The Pummerer rearrangements of cyclopropyl(methoxy)phenylsulfonium salts proceed via sulfur-stabilized carbocations to yield the title compounds.The sulfonium salts were prepared in high yields from olefins via carbene addition, oxidation, and methylation
SRN1 Reactions of Halocyclopropanes with Benzenethiolate Ion
Meijs, Gordon F.
, p. 606 - 611 (2007/10/02)
Ultraviolet irradiation of gem-dibromocyclopropanes 1 with benzenethiolate ion in liquid ammonia or in Me2SO solutions gave dithioacetals 2 and, in some cases, cyclopropyl phenyl sulfides 3.The reactions did not proceed in the dark and they were inhibited by m-dinitrobenzene, di-tert-butyl nitroxide, and oxygen.The bromocyclopropane 6a underwent a similar, but slower, reaction.Treatment of the bromochlorocyclopropane 7b led to replacement of only the bromine, while the dichlorocyclopropane 9b was inert under the reaction conditions.The results appear consistent with a radical chain mechanism.
Reaction of 7,7-Dibromobicycloheptane and 7-Bromobicycloheptane with Nucleophiles by a Radical Chain Mechanism
Meijs, Gordon F.
, p. 3863 - 3865 (2007/10/02)
7,7-Dibromo- and 7-bromobicycloheptane undergo substitution with certain nucleophiles by a radical chain process.
