A palladium-catalyzed [4 + 3] annulation of 2-bromobiphenyls and epoxides for the construction of dihydrodibenzo[b,d]oxepines is reported. This approach involves direct C–H and C–O bond activation followed by a ring annulation and features readily available starting materials, a broad substrate scope, good step economy and good scalability.
报道了钯催化的 2-溴联苯和环氧化物的 [4 + 3] 环化反应,用于构建二氢二苯并 [ b , d ]oxepine。这种方法涉及直接的 C-H 和 C-O 键激活,然后进行环化,具有易于获得的起始材料、广泛的底物范围、良好的步骤经济性和良好的可扩展性。
Synthesis of 9,
<scp>10‐Phenanthrenes</scp>
via Rh(
<scp>III</scp>
)‐Catalyzed [4+2] Annulation of
<scp>2‐Biphenylboronic</scp>
Acids with Diazo Compounds
A Rh(III)-catalyzed, transmetalation triggered C—Hactivation/annulation of 2-biphenylboronic acids with diazo compounds from β-keto esters or 1,3-dicarboxylates has been developed, leading to the synthesis of two kinds of 9,10-phenanthrenes. Notably, a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine, which was further verified
Application of Sulfoxonium Ylides or Iodonium Ylides in Rhodium‐Catalyzed Synthesis of Phenanthrenes
作者:Xiao Liu、Bingxin Zhou、Kelu Yan、Jiangwei Wen、Qiuyun Li、Xutong Wang、Xiu Wang
DOI:10.1002/adsc.202301451
日期:2024.4.23
The transmetalation triggered rhodium‐catalyzed C‒H bond activation and tandem annulation of 2‐biphenylboronic acids with sulfoxonium ylides or iodonium ylides has been developed. Various products of phenanthrenes were constructed under redox‐neutral conditions in 34−86% yields. Several mechanism exploration experiments and derivatization reactions were conducted in sequence to gain a deeper understanding