Derivatives of P-Amino- and Alkoxy-substituted Phosphanides as Synthetic Building Blocks

点击翻译按钮获取中文摘要

The coupling of nucleophilic alkali metal phosphanides R1R2PM or their borane complexes with electrophiles is one of the basic methods for incorporation of phosphorus atoms into molecular frame-works and has been used in many syntheses of phosphane derivatives in (element)organic chemistry, catalysis, or coordination chemistry. In this project, previously unknown phosphanide derivatives will be produced, whose phosphorus atoms carry electron withdrawing amino and alkoxy substituents. Species of this type are of interest as synthetic building blocks because of the possibility of using a nucleophilic reagent to transfer a phosphorus atom of electrophilic character to an electrophilic substrate. This reaction pattern can also be understood in the sense of a polarity reversal of the transferred phosphanyl fragment and opens up a synthetic strategy, which is complementary to the established use of phosphanides as a source of nucleophilic phosphanyl moieties and can be expected to have a great potential for the assembly of phosphines with substitution patterns that were hitherto difficult or impossible to realize. Concrete focus of the project is the elaboration of rational syntheses for defined borane adducts of metal-diamino- and dialkoxyphosphanides, their comprehensive characterization, and the thorough evaluation of their chemical reactivity. In the process, syntheses for diamino-/dialkoxy phosphines with an additional electropositive substituent are to be worked out, and their chemistry, which has been widely neglected so far, is to be developed. As a particular challenge, evidence obtained during preparatory work will be pursued, according to which metallated diamino-phosphanes could also be suitable as a "phosphinidene source" for the transfer of phosphorus (I) fragments.