Applications of chiral N-phosphinyl auxiliaries
Chiral auxiliary chemistry is one of the rapidly developing areas in asymmetric synthesis. The advantages in applications of chiral auxiliaries include high reliability, efficiency, and selectivity in asymmetric transformations. Several universal chiral auxiliaries, such as Evan’s auxiliary and tert-butanesulfinamides, have been developed since the concept of chiral auxiliaries was formed. Our research group has focused on new chiral auxiliaries based on N-phosphonyl amides, and these new auxiliaries have provided efficient asymmetric induction for many different reactions. Recently, we have developed a series of chiral N-phosphinyl auxiliaries. One of the most surprising facts is that we found that products with our auxiliaries are solids, and can be purified simply by washing with common organic solvents. This concept has been termed Group-Assisted Purification (GAP).