Premium
Synthesis and Structures of [2. n ]Metacyclophan‐1‐enes and their Conversion to Highly Strained [2. n ]Metacyclophane‐1‐ynes
Author(s) -
Akther Thamina,
Islam Md. Monarul,
Kowser Zannatul,
Matsumoto Taisuke,
Tanaka Junji,
Rahman Shofiur,
Alodhayb Abdullah,
Georghiou Paris E.,
Redshaw Carl,
Yamato Takehiko
Publication year - 2020
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202000548
Subject(s) - chemistry , halogenation , density functional theory , ring (chemistry) , cyclophane , stereochemistry , crystallography , computational chemistry , crystal structure , organic chemistry
The syntheses of syn ‐[2. n ]metacyclophan‐1‐enes ( n = 5, 6, 8) in good yields using the McMurry cyclization of 1, n ‐bis(3‐formyl‐4‐methoxyphenyl)alkanes are reported. Conversion of syn ‐[2.6]‐ and [2.8]metacyclophan‐1‐enes to the corresponding highly strained syn ‐type [2.6]‐ and [2.8]metacyclophane‐1‐ynes was achieved by successive bromination and dehydrobromination reactions. An attempted trapping reaction of the putative corresponding [2.5]metacyclophane‐1‐yne by Diels–Alder reaction with 1,3‐diphenylisobenzofuran failed due to its smaller ring size and strained structure. X‐ray crystallographic analyses show that the triple bonds in syn ‐[2.6]‐ and [2.8]metacyclophane‐1‐ynes are distorted from linearity with bond angles of 156.7° and 161.4°, respectively. A DFT (Density Functional Theory) computational study was conducted to determine the stabilities of different conformations of the target compounds.