Cyclic Phosphine Oxides and Phosphinamides from Di-Grignard Reagents and Phosphonic Dichlorides: Modular Access to Annulated Phospholanes

The
reaction between 1,4-di-Grignard reagents and phosphonous­(III)
dichlorides is a classical method for the direct synthesis of phospholanes.
Reported here is an extension of this approach to the preparation
of value-added, annulated phospholane oxides, achieved through the
combination of carbocyclic-fused di-Grignard reagents and readily
available phosphonic­(V) dichlorides. The procedure is amenable to
(benz)­annulation at both the 2,3- and 3,4-positions of the phospholane
ring, and a variety of aliphatic, cyclic and aryl P-electrophiles
are tolerated in reasonable to excellent yields.

1,4-二格氏试剂（1,4-di-Grignard reagents）与二氯化亚膦(III)（phosphonous(III) dichlorides）的反应是直接合成膦杂环戊烷（phospholanes）的经典方法。本文报道了该方法的拓展应用：通过结合碳环稠合二格氏试剂与易得的二氯化膦(V)（phosphonic(V) dichlorides），可制备高附加值的稠合膦杂环戊烷氧化物（annulated phospholane oxides）。该合成路径可在膦杂环戊烷环的2,3-位与3,4-位实现(苯并)稠合反应（(benz)annulation），且多种脂肪族、环状及芳基亲电磷试剂（P-electrophiles）均能兼容该反应，收率可达适中至优异水平。