Activation of CS 2 with the 2 H -Phosphindole Complex to Construct P,S-Polycycles.

The activation of CS 2 by the 2 H -phosphindole complex with a low-coordinate phosphadiene moiety is reported. The successive hetero-Diels-Alder reaction between 2 H -phosphindoles and CS 2 constructs two bridged rings and one spirocycle simultaneously, affording structurally complex P,S-polycyclic products. The two 2 H -phosphindoles approach the C═S bond in a head-to-head disposition to minimize steric hindrance. This work reveals the unique reactivity of low-coordinate organophosphorus species and their potential applications in small molecule activation.