Palladium catalyzed nucleoside modifications methods using nucleophiles and carbon monoxide

A method for the preparation of a pyrimidine nucleoside modified at the 5- or 6- position of the pyrimidine ring comprising the steps of:

• a) preparing a solution of a palladium catalyst, wherein said palladium catalyst is selected from the group consisting of PdL.sub.3 or PdL.sub.4, wherein L is a ligand of palladium;
• b) reacting a pyrimidine starting material containing a halogen leaving group attached to the 5- or 6- position of said pyrimidine starting material with a nucleophile and carbon monoxide in the presence the palladium catalyst;
• and
• c) isolating and purifying said pyrimidine nucleoside.

A compound selected from the group consisting of:

• ##STR34## wherein, Y is selected from the group consisting of O, NH and NR.sup.1 ;
• and
• R and R' are independently selected from the group consisting of a C1-C20 alkyl, C2-C20 alkenyl, aryl, and an amino acid, wherein R and R' are optionally part of a cyclic structure selected from an aromatic, aliphatic, or heterocyclic;
• and
• Z is selected from the group consisting of a ribose, deoxyribose, and dideoxyribose.

A compound selected from the group consisting of:

• ##STR37## wherein, Y is selected from the group consisting of SR', NHR' and NR'R";
• R' and R" are independently selected from the group consisting a C1-C20 alkyl, C2-20 alkenyl, aryl, natural amino acids and unnatural amino acids, wherein R' and R" can optionally be part of a cyclic structure which can be aromatic, aliphatic, or heterocyclic;
• and
• Z is selected from the group consisting of a ribose, deoxyribose and dideoxyribose.