A new route to 1,5-disubstituted 4-arylsulfonylpyrazoles by lithiation of 1-methyl-4-arylsulfonylpyrazoles
摘要:
The arylsulfonylvinamidinium salts 1 reacted with hydrazine in refluxing ethanol to give rise to 4-arylsulfonylpyrazoles 2 in reasonable yield. Regioselective lithiation of N-methylpyrazoles 3 with LDA followed by treatment with various electrophiles afforded the corresponding 1,5-disubstituted 4-arylsulfonylpyrazoles 5 in good yield.
A new route to 1,5-disubstituted 4-arylsulfonylpyrazoles by lithiation of 1-methyl-4-arylsulfonylpyrazoles
摘要:
The arylsulfonylvinamidinium salts 1 reacted with hydrazine in refluxing ethanol to give rise to 4-arylsulfonylpyrazoles 2 in reasonable yield. Regioselective lithiation of N-methylpyrazoles 3 with LDA followed by treatment with various electrophiles afforded the corresponding 1,5-disubstituted 4-arylsulfonylpyrazoles 5 in good yield.
Using a simple copper(I) catalyst has allowed a high yielding sulfonylative-Suzuki–Miyaura cross-coupling reaction to be developed. The process provides a single step route to diaryl sulfones from the direct combination of aryl boronic acids, sulfur dioxide and aryl iodides, and represents the first sulfonylative variant of a classic cross-coupling reaction. Sulfur dioxide is delivered from the surrogate