Syntheses and Properties of Medium-Sized Metacyclophanediynes

Abstract

The syntheses of [11]metacyclophane-2,9-diyne (3), [4.4]metacyclophane-2,12-diyne (4), [4.4]orthometacyclophane-2,12-diyne (5), (Z)-[10]metacyclophane-5-ene-2,8-diyne (6), [10]metacyclophane-2,8-diyne (7), and 5-isopropylidene[9]metacyclophane-2,7-diyne (8) have been achieved. The systems could be stabilized by protecting the triple bonds in 3−8 with the Co2(CO)6 moiety. PE spectroscopic investigations of 3 and 6−8 gave no clear-cut evidence for homoconjugative interactions among the π fragments. The triple bonds in 3−8 could be transformed into the corresponding cis double bonds by applying 2−5 molar equiv of Schwartz's reagent (28). Treatment of 3, 4, and 7 with t-BuOK allows the transformation of the propargylic moieties into allenic moieties, whereas the same treatment of 5 and 6 transforms the 2-butynyl bridges into 1,3-butadiene bridges, giving rise to several isomers. The structural assignments of 3−8 and their reaction products are based on their spectroscopic properties.

An efficient synthesis of isotope‐labeled PD0331179 and its labeled metabolite

“…From our literature search, we found that p-chloro-substituted phenylpropyne 9a was prepared by coupling p-cloro-benzylchloride with Grignard reagent. 10 By adapting this method, we can synthesize the labeled phenylpropyne 9b. However, it was found that phenylpropyne was very volatile and not easy to isolate in a small scale (Scheme 2).…”

“…From our literature search, we found that p‐chloro‐substituted phenylpropyne 9a was prepared by coupling p‐cloro‐benzylchloride with Grignard reagent . By adapting this method, we can synthesize the labeled phenylpropyne 9b .…”

Crystal structures of two bis(iodomethyl)benzene derivatives: similarities and differences in the crystal packing

“…(I) is used particularly in the synthesis of polycyclic aromatic systems (see for example: Takahashi et al 2006;Abreu et al, 2010;Wang et al, 2012). Similarly (II) has been used in polymer formation (Pandya & Gibson, 1991), in the synthesis of metacyclophanes (Ramming & Gleiter, 1997) and to provide aromatic spacers in organic synthesis (Kida et al, 2005). Our interest in such compounds is as components of ionene polymers.…”

Synthesis and structure of a chiral areno-bridged [2.4]metacyclophane

“…5 Ramming and Gleiter reported the syntheses of [n]MCP-diynes and the conversion of propargylic into allenic moieties as well as reactions with strong bases. 6 The brominationdehydrobromination reactions of the corresponding [2.n]MCPenes to strained [2.n]MCP-ynes possessing bent triple bonds was reported by For over three decades, the McMurry reaction and other Ti based reductive couplings have been effectively applied to the synthesis of cyclophanes. A one-step route to alkenecontaining cyclophanes is provided by the McMurry reaction which also allows for the generation of moderately strained cyclophanes.…”