124778-33-2Relevant academic research and scientific papers
Medium-size cyclophanes, 751 synthesis of anti-[2.3] metacyclophan-1ene and conversion to syn-1,2-epoxy[2.3]metacyclophane
Saisyo, Tatsunori,Shiino, Mikiko,Hironaka, Tohru,Yamato, Takehiko
, p. 141 - 143 (2007)
McMurry cyclisation of 1,3-bis(5-formyl-2-methoxyphenyl)propane afforded anti-6,13-dimethoxy[2.3]metacyclophan-1-ene, which was converted to the corresponding syn-1,2-epoxyl[2.3]metacyclophane by treatment of m-chloroperbenzoic acid.
Synthesis and structures of [2.n]metacyclophane-1,2-diones
Saisyo, Tatsunori,Shiino, Mikiko,Shimizu, Tomoe,Paudel, Arjun,Yamato, Takehiko
experimental part, p. 479 - 483 (2009/06/30)
McMurry cyclisation of 1,n-bis(5-formyl-2-methoxyphenyl)alkanes afforded dimethoxy[2.n]metacyclophan-1-enes and dimethoxy[2.n]metacyclophane-1,2-diols, in which latter one was converted to dimethoxy[2.n]metacyclophane- 1,2-diones by Albright-Goldman oxidation.
Synthesis, modification, and characterization of a family of homologues of exo-calix[4]arene: exo-[n.m.n.m]Metacyclophanes, n,m ≥ 3
Burns, Dennis H.,Chan, Ho-Kit,Miller, Jeffrey D.,Jayne, Charles L.,Eichhorn, David M.
, p. 5185 - 5196 (2007/10/03)
A general strategy for the preparation of the family of exo-[n.m.n.m]metacyclophanes (n,m ≥ 3) in 6-steps (starting from 2-bromoanisole)that utilizes a [2 + 2] approach to furnish the exometacyclophane ring in good to moderate yield is described. The soluble copper catalyst [CuBr- LiSPh-LiBr-THF] is used to efficiently couple Grignard and alkyl or ether tosylate reagents in several of the synthetic steps, including the ring construction in the final step. The exo-[n.m.n.m]- metacyclophane ring is conformationally mobile on the NMR time scale, and X-ray crystallography reveals that exo-[3.3.3.3]metacyclophane 2a assumes a cone conformation, and that exo-[6.6.6.6]- metacyclophane 6a assumes a chair conformation. Molecular mechanics calculations show that both conformations for each exo-metacyclophane are very similar in energy. Regiocontrol over the alkylation and acylation of the phenolic oxygens of 2b is problematic, although the preparation of the tetraacetylated 18 and alkylation of 2b with CH2BrCl to furnish the methylene-linked mono- and bis-adducts 19 and 20 are straightforward.
Scope and utility of a new soluble copper catalyst [CuBr-LiSPh-LiBr-THF]: A comparison with other copper catalysts in their ability to couple one equivalent of a Grignard reagent with an alkyl sulfonate
Burns, Dennis H.,Miller, Jeffrey D.,Chan, Ho-Kit,Delaney, Michael O.
, p. 2125 - 2133 (2007/10/03)
A mixture of equal amounts of CuBr-SMe2, LiBr, and LiSPh in THF at 0°C furnished a new soluble copper catalyst that was highly efficient at coupling primary, secondary, tertiary, aryl, vinyl, and allylic Grignard reagents to primary tosylates and primary Grignard reagents to secondary tosylates and mesylates, all with the use of only 1 equiv of Grignard reagent. The new catalyst was shown to be much more reactive than copper catalysts CuBr and Li2CuCl4 and more efficient in the transference of secondary and tertiary alkyl groups than lower order cuprates (Gilman reagents) and demonstrated more reactivity than the lower order cuprates with its ability to couple primary Grignard reagents to secondary sulfonates. The Grignard reagent/catalyst system was compatible with an ester functionalized tosylate, thus proving to be more chemoselective than a Grignard reagent without the catalyst. The catalyst exhibited good reactivity below room temperature, and with the addition of 6% v/v of HMPA to the catalyst solution, excellent yields of coupled product were obtained within a 25-67°C temperature range. 1H NMR demonstrated that the catalyst solution consisted of several species that most likely were composed of copper ligated with thiophenol, THF, and LiBr in aggregated forms.
Synthesis of 6,16,22,32-tetrahydroxy[3.3.3.3]metacyclophane with the aid of a new copper catalyst
Burns, Dennis H.,Miller, Jeffrey D.
, p. 5189 - 5192 (2007/10/02)
Metacyclophane 2 has been prepared in 4 steps starting from 2- bromoanisole with the aid of a new copper catalyst. The catalyst was prepared by mixing CuBr-SMe2 with LiSPh and LiBr in THF.
