The subject described by the author is very interesting and has high scientific potential and applicability. It is well known that phosphines are essential components in modern transformations, including Suzuki, Stille, Negishi, Buchwald, and Sonogashira coupling reactions. The editorial side of the manuscript is very good and clear. The manuscript consists of a table of contents, an introduction, seven chapters describing the reduction of P=O bond, conclusions, a list of abbreviations and references. It is a classic system that guarantees an effective presentation of research results extracted from the scientific literature. To summarize, I consider the presented manuscript as a valuable contribution. It is an excellent review devoted to the discussed reduction and it certainly will be of great interest to readers. Therefore, it deserves publication. An excerpt from the review