Dibenzophosphole oxides were obtained from secondary hydrophosphine oxides with a biphenyl group by dehydrogenation via phosphine–hydrogen and carbon–hydrogen bond cleavage in the presence of a catalytic amount of palladium(II) acetate, Pd(OAc)2. By using this reaction, a ladder-type dibenzophosphole oxide could also be synthesized by double intramolecular dehydrogenative cyclization.
A palladium‐catalyzed intramolecular directarylationreaction was developed and two efficient one‐pot sequentialdirectarylation/Suzuki–Miyauracoupling and intra/intermolecular directarylation reations were also realized. The method provides a simple and straightforward procedure for the synthesis and further functionalization of dibenzophosphole oxides from easily accessible ortho‐halodiarylphosphine
Catalytic Synthesis of Chiral Phosphole Oxides via Desymmetric C–H Arylation of o-Bromoaryl Phosphine Oxides
作者:Yu-Ming Cui、Li-Wen Xu、Yan Lin、Wei-Yang Ma、Qiao-Ying Sun
DOI:10.1055/s-0036-1588983
日期:2017.7
A palladium-catalyzed intramolecular direct arylation reaction of o-bromoaryl phosphine oxides was developed to afford a variety of P-stereogenic phosphole oxides in good yields. The enantioselectivities were closely associated with the specific structures of substrates, which ranged from 4–94%. As a result of ready availability of starting materials and simple operation to improve the enantioselectivities
开发了钯催化的邻溴芳基氧化膦的分子内直接芳基化反应,以良好的收率提供各种 P-立体氧化磷。对映选择性与底物的特定结构密切相关,范围为 4-94%。由于原料易得且操作简单以提高低 ee 值产物的对映选择性,该方法为合成 P-立体磷氧化物提供了一种简单直接的方法。
Synthesis of Dibenzophospholes by Tf<sub>2</sub>O-Mediated Intramolecular Phospha-Friedel–Crafts-Type Reaction
作者:Kazutoshi Nishimura、Koji Hirano、Masahiro Miura
DOI:10.1021/acs.orglett.9b00219
日期:2019.3.1
A Tf2O-mediated intramolecular phospha-Friedel–Crafts-type reaction of secondary biarylphosphine oxides has been developed. The reaction is promoted simply by Tf2O to form the corresponding dibenzophospholes under metal-free conditions. The starting substrates are readily available and easy-to-handle phosphine oxides, and the regioselectivity is controlled by the innate electronic nature. Thus, this