Synthesis and characterization of oxadisilole fused benzo[b]triphenylene

o-Silylaryl Triflates: A Journey of Kobayashi Aryne Precursors

“…In 2004, Cheng and co-workers demonstrated a Pd-catalyzed cocyclotrimerization of bicyclic alkenes 10-12 and o -silylaryl triflates, furnishing the corresponding norbornane anellated 9,10-dihydrophenanthrene derivatives 10-13 in moderate to excellent yields (Scheme a) . Similar type of reaction was later reported by Lee et al by using oxadisilole fused oxabicyclic alkenes 10-14 to obtain exo -adducts 10-15 (Scheme b) . In 2006, Peña, Pérez, and co-workers revealed that electron-deficient alkenes could participate in this Pd-catalyzed cocyclotrimerization reaction, which led to the production of dihydrophenanthrenes 10-16 by using PPh 3 as the ligand or ortho -olefinated biaryls 10-17 in the presence of P­( o -tol) 3 ligand (Scheme c) .…”

“…752 Similar type of reaction was later reported by Lee et al by using oxadisilole fused oxabicyclic alkenes 10-14 to obtain exo-adducts 10-15 (Scheme 212b). 753 In 2006, Penã, Peŕez, and co-workers revealed that electron-deficient alkenes could participate in this Pd-catalyzed cocyclotrimerization reaction, which led to the production of dihydrophenanthrenes 10-16 by using PPh 3 as the ligand or ortho-olefinated biaryls 10-17 in the presence of P(o-tol) 3 ligand (Scheme 212c). 754 In 2018, Penã et al employed diiodo compound 10-18 as the precursor of pyramidalized alkene and achieved cyclotrimerized products 10-19 with arynes (Scheme 212d).…”

Iodonium Salts as Benzyne Precursors

“…pounds from benzobisoxadisilole. [100][101][102][103][104][105] The initial reactiono f benzobisoxadisilole and (diacetoxyiodo)benzene with TfOH generates an unstabled iaryliodonium triflate 72 as benzyne source,w hich then reacts with the trapping reagents in the presence of fluoride source to afford the corresponding benzyne adducts.I nas pecific example, the reactiono fb enzobisoxadisilole 71 with (diacetoxyiodo)benzene 42 involves the initial formation of diaryliodonium triflate 72 followed by cycloaddition reaction with furan 34 in the presenceo fTBAF to give the final product 73 in 88 %y ield (Scheme 24). [103] Following ground-breaking research of Kitamura and coworkers on the preparation and reactivity of phenyl[2-(trimethylsilyl)phenyl]iodonium triflate 48, [38] several research groups have reported that 1,2,4,5-tetrakis(trimethylsilyl)benzene 74 can be used as an efficient 1,4-benzdiyne synthone.…”

“…Lee and co‐workers have developed a two‐step one‐pot procedure for the preparation of oxadisilole‐fused cyclic compounds from benzobisoxadisilole . The initial reaction of benzobisoxadisilole and (diacetoxyiodo)benzene with TfOH generates an unstable diaryliodonium triflate 72 as benzyne source, which then reacts with the trapping reagents in the presence of fluoride source to afford the corresponding benzyne adducts.…”

4.09 Nucleophilic Coupling with Arynes

“…The hypervalent iodine aryne precursors (11 and 12) have originally been prepared from 1,2-bis(trimethylsilyl)-arenes, 74-81 whose synthesis requires severe conditions; however, an improved approach using benzoxadisilole 13 is also available (Scheme 10). [82][83][84][85][86] …”