14
2 Results and Discussion
(2.1f) as well as an unsubstituted phenyl (2.1g) and a para-methoxy phenyl (2.1h)
were tolerated. We were pleased to see that tosyl- protected glycine methyl ester
gave coupled product 2.1i in a good 63% yield (Figure 15). The possibility of
coupling N-tosylated amino acids opens up interesting applications.
Figure 15: Addition of tosyl and nosyl amides to the enolonium.
Since tosyl- and nosyl- sulfonamides proved to be suitable nucleophiles, in
this transformation, we further investigated other aromatic groups on the sulfonamide. An ortho-nitrophenylsulfonyl amide gave the aminated product 2.1j in a
similar yield as its isomer 2.1b while a naphthyl derivative 2.1k was comparable
to 2.1c. The 2-pyridinyl sulfonamide 2.1l was successfully obtained while its 4-nitro derivative 2.1m gave no product. In the last case, the sulfonamide may have
undergone decomposition and/or deprotection as none of it could be detected after
the reaction (Figure 16).
2 Results and Discussion
(2.1f) as well as an unsubstituted phenyl (2.1g) and a para-methoxy phenyl (2.1h)
were tolerated. We were pleased to see that tosyl- protected glycine methyl ester
gave coupled product 2.1i in a good 63% yield (Figure 15). The possibility of
coupling N-tosylated amino acids opens up interesting applications.
Figure 15: Addition of tosyl and nosyl amides to the enolonium.
Since tosyl- and nosyl- sulfonamides proved to be suitable nucleophiles, in
this transformation, we further investigated other aromatic groups on the sulfonamide. An ortho-nitrophenylsulfonyl amide gave the aminated product 2.1j in a
similar yield as its isomer 2.1b while a naphthyl derivative 2.1k was comparable
to 2.1c. The 2-pyridinyl sulfonamide 2.1l was successfully obtained while its 4-nitro derivative 2.1m gave no product. In the last case, the sulfonamide may have
undergone decomposition and/or deprotection as none of it could be detected after
the reaction (Figure 16).