A general and efficient method for the direct alkynylation of unactivatedC(sp3)-H bondsunder metal-free condition is described. The reaction smoothly performs undermildconditions and shows excellent functional-group tolerance....
A transition-metal-free synthetic method of various ynones via decarboxylative alkynylation of α-keto acids is described. The reaction is carried out undermildconditions and exhibits remarkable tolerance of functional groups. The mechanism of a radical process is proposed in the reaction.
Dual Hypervalent Iodine(III) Reagents and Photoredox Catalysis Enable Decarboxylative Ynonylation under Mild Conditions
作者:Hanchu Huang、Guojin Zhang、Yiyun Chen
DOI:10.1002/anie.201502369
日期:2015.6.26
combination of hypervalentiodine(III) reagents (HIR) and photoredoxcatalysis with visible light has enabled chemoselective decarboxylativeynonylation to construct ynones, ynamides, and ynoates. This ynonylation occurs effectively undermild reaction conditions at room temperature and on substrates with various sensitive and reactive functional groups. The reaction represents the first HIR/photoredox dual
Asymmetric alkynylation of thiazolones and azlactones with alkynylbenziodoxolones as the electrophilic alkyne source catalyzed by thiourea phosphonium salt is described. By using thiazolones as nucleophiles, the desired alkyne functionalized thiazolones were obtained in 55–89% yields with 31–86% ee. Azlactones gave the desired products in comparable yields with lower enantioselectivities. Ring-opening
描述了硫脲鏻盐催化的噻唑酮和吖内酯的不对称炔基化反应,其中炔基苯并氧唑酮作为亲电炔烃源。通过使用噻唑酮作为亲核试剂,以 55-89% 的产率和 31-86% 的 ee 获得所需的炔烃官能化噻唑酮。Azlactones 以较低的对映选择性以相当的产率得到所需的产物。炔基化产物的开环导致α,α-二取代的α-氨基酸衍生物有效而不会损失对映选择性。
Selective P−C(sp<sup>3</sup>
) Bond Cleavage and Radical Alkynylation of α-Phosphorus Alcohols by Photoredox Catalysis
作者:Kunfang Jia、Junzhao Li、Yiyun Chen
DOI:10.1002/chem.201800202
日期:2018.3.2
cleavage and radical alkynylation of α‐phosphorus alcohols to construct phosphonoalkynes is reported. The phosphorus radical is generated upon P−C bond cleavage reaction via the alkoxyl radical through photoredox catalysis with cyclic iodine(III) reagents. Various arylphosphinoyl‐, alkylphosphinoyl‐, phosphonate‐, and phosphonic amide alcohols serve as radical phosphorus precursors to construct phosphonoalkynes