Copper‐Catalyzed Formal [2+2+1] Heteroannulation of Alkenes, Alkylnitriles, and Water: Method Development and Application to a Total Synthesis of (±)‐Sacidumlignan D
作者:Tu M. Ha、Claire Chatalova‐Sazepin、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201604528
日期:2016.8
A copper‐catalyzed three‐component reaction of alkenes, alkylnitriles, and water affords γ‐butyrolactones in good yields. The domino process involves an unprecedented hydroxy‐cyanoalkylation of alkenes and subsequent lactonization with the creation of three chemical bonds and a quaternary carbon center. The synthetic potential of this novel [2+2+1] heteroannulation reaction was illustrated by a concise
ZnI<sub>2</sub>/Zn(OTf)<sub>2</sub>-TsOH: a versatile combined-acid system for catalytic intramolecular hydrofunctionalization and polyene cyclization
作者:Ting-Hung Chou、Bo-Hung Yu、Rong-Jie Chein
DOI:10.1039/c9cc07242j
日期:——
combined-acid system using a zinc(II) salt [ZnI2 or Zn(OTf)2] and p-toluene sulfonic acid (TsOH) was investigated for catalytic cationic cyclizations, including intramolecular hydrocarboxylation, hydroalkoxylation, hydroamination, hydroamidation, hydroarylation and polyenecyclizations. This reaction provides easy access to five- and six-membered O- and N-containing saturated heterocyclic compounds, tetrahydronaphthalene
challenging intramolecular hydroacyloxylation reaction. Both HFIP and an internal carboxy group have been proven to be crucial for the successful implementation of this transformation; these are proposed to assist the formation and stabilization of the key cationic intermediate via hydrogen-bondinginteractions with perrhenate anion (ReO4–).
该出版物描述了 Re 2 O 7在六氟异丙醇 (HFIP) 中的应用,用于活化惰性和电子失活的烯烃,以促进具有挑战性的分子内加氢酰氧基化反应。HFIP 和内部羧基均已被证明对于成功实施这一转变至关重要;这些被提议通过与高铼酸盐阴离子 (ReO 4 – )的氢键相互作用来帮助关键阳离子中间体的形成和稳定。