Synthesis of Decahydrocyclobuta[cd]indene Skeletons: Rhodium(III)‐Catalyzed Hydroarylation and Relay Thiophene‐Promoted Intramolecular [2+2] Cycloaddition

Abstract

The preparation of decahydrocyclobuta [cd]indene skeleton was accomplished through rhodium(III)-catalyzed hydroarylation and relay thiophene-promoted intramolecular [2 + 2] cycloaddition. This tandem reaction exhibited broad substrate scope (24 examples) and good functional group compatibility. Control experiments revealed the important role of sulfur (S) heteroatom, thus a tentative mechanism with thiophene-promoted double Michael additions was proposed to explain this formal [2 + 2] cycloaddition. Moreover, the resulting polycyclic products displayed potent anti-cancer activities against breast cancer cell lines MDA-MB-468.

Progress in the Synthesis of Hydrobenzofurans from O-Cyclohexadienone-tethered 1,6-Enynes

“…最 近, 林国强课题组 [24] 以吡啶等含氮杂环作为导向基团, 通过 Rh 催化, 实现了芳环 β 位 C-H 键对炔的芳基化/ 环化反应, 合成了一系列氢化苯并呋喃衍生物. 当芳基 为噻吩时, 相同条件下可以得到目标产物, 而将反应溶 剂由六氟异丙醇换成醋酸, 反应温度由 60 ℃提高到 100 ℃时, 噻吩 β 位 C-H 键对炔的芳基化反应, 形成 芳基烯基铑物种, 再经过质子化和两步 Michael 加成反 应可以得到含四元环结构的氢化苯并呋喃骨架 [25] . 控 制实验表明噻吩在两步 Michael 加成中起关键作用.…”

Rhodium(III)‐Catalyzed Regioselective C−H Annulation and Alkenylation of 2‐Pyridones with Terminal Alkynes

“…realized C−H alkenylation of various heteroarenes with terminal alkynes under Cp*Rh(III) catalysis [6c] . Recently, cascade annulations of (hetero)arenes with tethered terminal alkynes triggered by Cp*Rh(III)‐catalyzed C−H activation have been reported by the groups of Lin [6d,e] and Yi, [6f] respectively.…”

Rh(I)-Catalyzed [5 + 2]/[2 + 2] Cycloaddition Cascade to Access a Cyclobutane-Fused [4–5–6–7] Tetracyclic Framework

“…9 Subsequently, Lin and co-workers presented the first Rh(III)-catalyzed hydroarylation and thiophene-promoted intramolecular [2 + 2] cycloaddition cascade, leading to the formation of a [4−5− 6] tricyclic framework (eq 3, Scheme 1). 10 Although these excellent approaches for the preparation of cyclobutanes and their derivatives are available, it is still highly desirable to further explore alternative methodologies in the pursuit of molecular diversity for further functional studies.…”