Nonplanar Tub-Shaped Benzocyclooctatetraenes via Halogen-Radical Ring Opening of Dihydrobiphenylenes

Abstract

A novel tandem Ru-catalyzed [2+2+2] cycloaddition of arylenynes to dihydrobiphenylenes followed by halogen-radical ring opening has been developed for the construction of tub-shaped halogenated benzocyclooctatetraenes (bCOT’s). Cross-couplings and Diels–Alder reactions of the brominated bCOT’s allow the formation of the corresponding eight-membered ring-fused PAH’s. The halogen-radical ring opening probably occurs via a selective formation of a bis-allyl radical at the 1,3-cyclohexadiene moiety, halogenation at the bridgehead carbon, and finally electrocyclic ring opening.

Accurate Crystal Structures of C12H9CN, C12H8(CN)2, and C16H11CN Valence Isomers Using Nonspherical Atomic Scattering Factors

“…Values from structures introduced in this paper are included in this average unless otherwise specified. Comparators used in this category: BUYYUP, CUDYUV, FIVHIB, LEZMAE, LIPVAJ, QOGYER, QOGZAO, OWUVUA, OWUWAH, OWUWEL d Statistical outlier omitted from the averaged values. …”

“…Values from structures introduced in this paper are included in this average unless otherwise specified. Comparators used in this category: BUYYUP, 93 CUDYUV, 94 FIVHIB, 95 LEZMAE, 17 LIPVAJ, 96 QOGYER, 97 QOGZAO, 82 OWUVUA, 32 OWUWAH, 32 OWUWEL. 32 In endo-1-1,2,2a,8b-tetrahydrocyclobuta[a]naphthalenecarbonitrile, 9 (P2 1 2 1 2 1 , Z′ = 1) and endo-2-1,2,2a,8btetrahydrocyclobuta[a]naphthalenecarbonitrile, 10 (P2 1 /n, Z′ = 1), both of the nitrile substituents are oriented in toward the fold created by the ring fusions (Figure 4c,d).…”

“…In pursuit of this goal, Bello-Garcia et al have contributed a large number of easily accessible functionalized benzocyclooctatetraenes, BCOTs (benzo [8]annulenes, IV in Chart 1), via Ru-catalyzed [2 + 2 + 2] cycloaddition of arylenynes to dihydrobiphenylenes followed by a straightforward ring opening reaction. 32 Even with this significant contribution, structures of simple BCOTs remain rare, with only 11 structures currently reported in the CSD.…”

Fabrication of Nitrogen Based Magnetic Conjugated Microporous Polymer for Efficient Extraction of Neonicotinoids in Water Samples

“…Pure water was provided by the Ecology Institute of the Shandong Academy of Sciences, and the actual water samples were collected from tap water, rainwater and Rainbow Lake water (Jinan, China). The 1,4-dibromo-2,5-bis(bromomethyl)benzene and Fe 3 O 4 were synthesized according to the reported procedures [53,54].…”