Bridged [18]annulenes. A study of the synthesis and properties of 12c,12d,12e,12f-tetrahydrobenzo[g,h,i]perylene and its analogs

Synthesis and structure of 4,6-disubstituted dibenzothiophenes and their use in the preparation of binuclear platinum(ii) complexes

“…16 Under reflux in carbon disulfide, this method resulted in variable yields. [19][20][21] Very low yields of 1 were obtained when using dichloromethane as solvent, 22 but the reaction of 5-methyldibenzo[b,d]thiophenium tetrafluoroborate with bromine gave satisfactory yields. 22,23 An improved method of synthesis utilises the free radical brominating agent N-bromosuccinimide, NBS, under mild conditions with chloroform as solvent.…”

Theory of Coronoid Hydrocarbons

“…9) was prepared relatively early by Cram and Dewhirst (1959). It is mentioned in a work by DuVernet et al (1978) and, together with Sl' S2 and S4' by . The preparations of dibenzo [ab,de][18]annulene (S7) and phe~o…”

Condensed Benzenoid Cyclophanes

“…Ring contraction of 160 gave good yields of the [2.2]cyclophane 163. An alternative route to diene 165 159 employed the benzyne-Stevens rearrangement procedure 45 and commenced with compound 158. 98 ' 99 -158 The diene 165 was made 157 by subjecting 158 to a Wittig rearrangement, 17 oxidizing the resulting product to a disulfoxide, and effecting a thermal elimination of methylsulfenic acid.…”

“…157 Similar observations were made in other paracyclophane systems. In the presence of oxygen 159 or 164 165 166 167 iodine, 157 oxidation proceeded to produce coronene (3) quantitatively. An alternative route to diene 165 159 employed the benzyne-Stevens rearrangement procedure 45 and commenced with compound 158.…”

“…98 ' 99 -158 The diene 165 was made 157 by subjecting 158 to a Wittig rearrangement, 17 oxidizing the resulting product to a disulfoxide, and effecting a thermal elimination of methylsulfenic acid. Boekelheide and co-workers reported 159 the synthesis of several other related cyclophanedienes, including the dihydrophenanthrene cyclophanediene 167, 160 all of which cyclized in a manner similar to the cyclization of bridged annulenes. A degassed solution of diene 165 on exposure to light changed color to deep orange and gave an Ή-ηπίΓ spectrum indicative of the bridged annulene 166 (the shielded internal protons were observed at δ -2.74 to -3.02).…”