Utilization of Aminophosphonates in the Petasis Boronic Acid Mannich Reaction

Aminophosphonates were used as amine components in the Petasis boronic acid Mannich reaction. With the use of a-ami- nophosphonates, several N-phosphonomethylglycine derivatives were prepared in modest to good yields and high diastereoselectiv- ities. The method affords the possibility of variation for the substit- uents in the position a to the phosphorus and nitrogen atoms. By using the same methodology, highly functionalized amino acids were prepared starting from (R)-b-amino-a,a-difluoromethylphos- phonate.