Phosphonic dihalides synthesis

The synthesis of chiral phosphine oxides has stimulated effort in a number of laboratories in recent years. An elegant new approach to the problem involves the use of sugar-derived phosphorus heterocycles. These are 1,3,2-dioxa-phosphorinan-2-ones, such as (1), formed from glucosides and various phosphonic dihalides, such as (2). The preparation of chiral phosphine oxides... 

In 1988, it was discovered that 3-phospholenes can be prepared directly by the reaction of zirconium metallocycles with phosphonous dihalides (Equation (50)) <88JA2310>. The synthesis of only one phospholene (3,4-dimethyl-l-phenyl) has been reported so far, but the method appears to have a good chance of possessing valuable versatility. 

Phospholenes generally have an envelope-shaped conformation (6.884). The most versatile method for the synthesis of phospholenes is the McCormack cycloaddition reaction using a diene and a phosphonous dihalide or a phosphorus trihalide [63,64]. 

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