170167-19-8Relevant academic research and scientific papers
Synthesis and Diels-Alder reactions of 1,2-dimethylene[2.n]metacyclophanes
Yamato, Takehiko,Miyamoto, Shinpei,Hironaka, Tohru,Miura, Yoshinori
, p. 3 - 6 (2007/10/03)
(Chemical Equation Presented) The Diels-Alder reaction of 1,2-dimethylene[2.n]MCPs (MCP = metacyclophane) with suitable dienophiles followed by aromatization and photoinduced or FeCl3-induced transannular cyclization afforded phenanthrene-anell
Medium-sized cyclophanes. Part 58. Synthesis and conformational studies of [2.n]metacyclophan-1-enes and [n.1]metacyclophanes
Yamato, Takehiko,Fujita, Koji,Tsuzuki, Hirohisa
, p. 2089 - 2097 (2007/10/03)
A series of syn- and anti-[2.n]metacyclophan-1-enes and [2.n]metacyclophane-1,2-diols are prepared in good yields by a McMurry cyclization of 1,n-bis(5-acetyl-2-methoxyphenyl)alkanes. Interestingly, in the same coupling reaction in the absence of pyridine the pinacol rearrangement of [2.n]metacyclophane-1,2-diols to afford [n.1]metacyclophanes is observed, attributable to the TiCl4 or acids generated from the McMurry reagent occurring during the cyclization reaction. In fact, protic acid- or Lewis-acid induced pinacol rearrangements of [2.n]metacyclophane-1,2-diols afford [n.1]metacyclophanes in good yield. The [2.n]metacyclophan-1-ene-to-[n.1]metacyclophane ratio of the products is strongly governed by the number of the methylene bridges. The proportion of the rearrangement product increases with increasing length of the bridge. Conformational studies of [n.1]metacyclophanes as well as of [2.n]metacyclophan-1-enes in both solution and solid state are also described.
Friedel-Crafts ipso-Acylations of 2-Substituted 4-tert-Butylanisoles and p-tert-Butylmethoxymetacyclophanes
Yamato, Takehiko,Maeda, Kenji,Kamimura, Hideo,Noda, Kozo,Tashiro, Masashi
, p. 1865 - 1889 (2007/10/03)
Acylation of 1,n-bis(5-tert-butyl-2-methoxyphenyl)alkanes 6 with acid chloride or acid anhydride in the presence of Lewis acids afforded only the product arizing from two-fold ipso-acylation at the tert-butyl groups; similar reaction of 1,2-bis(5-tert-butyl-2-methoxy-3-methylphenyl)alkanes 8 led only to the recovery of the starting compounds, thus differing from the nitration of 8 with fuming HNO3 at room temperature which affords in quantitative yield the selective ipso-nitration product at the tert-butyl groups.However, the ipso-acylation reactions of 5,13-di-tert-butyl-8,16-dimethoxymeta-cyclophane 15 led to the first-reported direct introduction of an acyl group due to a through-space electronic interaction with the opposing benzene ring.In contrast the selective ipso-acylation reaction was not observed in the case of the larger ring sized macrocyclic meta-cyclophane, p-tert-butyltetramethoxycalix(4)arene.
