Synthesis of 2,2‐Disubstituted 2H‐Chromenes through Carbon‐Carbon Bond Formation Utilizing a [1,2]‐Phospha‐Brook Rearrangement under Bronsted Base Catalysis
Synthesis of 2,2‐Disubstituted 2H‐Chromenes through Carbon‐Carbon Bond Formation Utilizing a [1,2]‐Phospha‐Brook Rearrangement under Bronsted Base Catalysis
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布朗斯台德碱催化下利用[1,2]-磷酸-布鲁克重排通过碳-碳键形成合成2,2-二取代2H-色烯
DOI：
10.1002/chem.202201198
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Terada Masahiro
中科院分区：
文献类型：
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作者：
Kondoh Azusa;Terada Masahiro
利用Brønsted碱催化下的[1，2]-磷杂-Brook重排反应，发展了一种合成2，2-二取代2 H-色烯的新方法。磷腈P2-tBu有效催化含有二乙氧基磷酰基的4 H-色烯-4-醇与α，β-不饱和酮的加成反应，该反应涉及通过[1，2]-磷杂-布鲁克重排和随后的2-位共轭加成催化生成碳负离子，以高度非对映选择性的方式提供具有烯基磷酸酯部分的加合物。基于与芳基锌试剂的镍催化的交叉偶联反应的加合物的进一步转化提供了密集官能化的2，2_二取代的2 H-色烯。
A new methodology for the synthesis of 2,2‐disubstituted 2H‐chromenes was developed by utilizing the [1,2]‐phospha‐Brook rearrangement under Brønsted base catalysis. Phosphazene P2‐tBu efficiently catalyzed the addition reaction of 4H‐chromen‐4‐ols containing a diethoxyphosphoryl group withα,β‐unsaturated ketones, which involved the catalytic generation of a carbanion through the [1,2]‐phospha‐Brook rearrangement and subsequent conjugate addition at the 2‐position to afford adducts possessing an alkenylphosphate moiety in a highly diastereoselective manner. Further transformation of the adducts based on a nickel‐catalyzed cross‐coupling reaction with arylzinc reagents provided densely functionalized 2,2‐disubstituted 2H‐chromenes.