AC Kolloquium - Prof. Dr. Jan J. Weigand (TU Dresden)

"Unlocking the Potential of π-Conjugated Azaphospholes and Innovative P1 Building Blocks"

In our pursuit of tailored compounds, we explore two research frontiers. First, we introduce a streamlined method to craft σ²λ³-1,3-azaphospholes from common alkynes. A [3+2]-cycloaddition with imidazoliumyl substituted triflato-phosphanes yields azaphospholium salts, readily reducible to azaphospholes. This versatile process achieves impressive yields, offering access to diverse examples with yields up to 99%. We delve into mechanistic insights, unveiling the chemical choreography.
Shifting focus, we present innovative P₁ building blocks embodied by cationic imidazoliumyl-phosphinidene [L_C−P]⁺. Overcoming the scarcity of isolable phosphinidenes, we design a phosphinidene with a strategic leaving group. Its transfer initiates various transformations, including thioketone conversion to cationic phosphaalkenes. [...]