Organic Chemistry Portal

Abstracts

Search:

Selective C-P(O) Bond Cleavage of Organophosphine Oxides by Sodium

Jian-Qiu Zhang, Eiichi Ikawa, Hiroyoshi Fujino, Yuki Naganawa, Yumiko Nakajima and Li-Biao Han*

*National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan, Email: libiao-hanaist.go.jp

J.-Q. Zhang, E. Ikawa, H. Fujino, Y. Naganawa, Y. Nakajima, L.-B. Han, J. Org. Chem., 2020, 85, 14166-14173.

DOI: 10.1021/acs.joc.0c01642


see article for more reactions

Abstract

Sodium exhibits better efficacy and selectivity than Li and K for converting Ph3P(O) to Ph2P(OM). A subsequent reaction with alkyl halides or with aryl halides in the presence of a Pd catalyst provides phosphine oxides in good to excellent yields.

see article for more examples



Details

The document discusses the selective cleavage of C−P(O) bonds in organophosphine oxides using sodium (Na), which shows better efficacy and selectivity compared to lithium (Li) and potassium (K). The study reveals that Na can efficiently convert triphenylphosphine oxide (Ph3P(O)) to diphenylphosphine oxide (Ph2P(ONa)) with high yields. The reaction involves the co-generation of PhNa, which decomposes quickly in THF. The research also explores the reactivity of various alkyl and aryl halides with Ph2P(ONa), producing corresponding phosphine oxides in good to excellent yields. The study highlights the superior selectivity of Na for C−P bond cleavage over Li and K, making it a promising method for synthesizing organophosphine oxides. Additionally, the document details the experimental procedures, including the use of palladium-catalyzed cross-coupling reactions to produce diphenyl(aryl)phosphine oxides. The findings suggest a single electron transfer (SET) mechanism for the cleavage of the P−R bond. The research was supported by the National Institute of Advanced Industrial Science and Technology (AIST) and Katayama Chemical Industries Co., Ltd., with no competing financial interests declared by the authors.


Key Words

Phosphine Oxides, Sodium


ID: J42-Y2020