Dual Photoredox/Cobalt-Catalyzed Reductive Cyclization of Alkynals
作者:Kento Nakamura、Hina Nishigaki、Yoshihiro Sato
DOI:10.1021/acscatal.3c06206
日期:2024.3.1
alkynals using H2O for the catalyst turnover. This method was applied to aliphatic and aromatic aldehydes for five-, six-, and seven-membered (heterocyclic) ring formation with various substitutions on alkyne units. This H2O-added protocol was further developed into a one-pot transformation fromacetals through in situ generated aldehydes, which shortened the synthetic path of the reaction.
取代环醇是药学上必需的支架之一。在这里,我们报道了使用 H 2 O进行催化剂周转的光氧化还原/钴催化的炔醛还原环化。该方法适用于脂肪族和芳香族醛,形成五元、六元和七元(杂环)环,并在炔单元上进行各种取代。这种添加H 2 O的方案进一步发展为从缩醛到原位生成醛的一锅转化,从而缩短了反应的合成路径。
groups in products are facilely late-stage functionalized in accessing numerous derivatives, as well as the enantio-enrichment of exocyclic allyl alcohol using chiral ligands. Mechanistic studies suggest that bipyridine-ligated Cr(II) complex serves as a reactive catalyst enabling the generation of the ketyl radical for coupling, giving vinyl radical, followed by the combination of Cr and transmetalation