The present invention provides compounds of formula (I)
1
wherein R
1
, R
2
, R
3
, R
4
and X are as defined in the specification, and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prophylaxis of diseases which are associated with DPP IV, such as diabetes, particularly non-insulin dependent diabetes mellitus, and impaired glucose tolerance.
A novel domino strategy for forming poly-substituted quaternary imidazoles through a Cs2CO3-promoted aryl migration process
作者:Hai-Wei Xu、Wei Fan、Meng-Yuan Li、Bo Jiang、Shu-Liang Wang、Shu-Jiang Tu
DOI:10.1039/c3ob40666k
日期:——
A new dominostrategy for the synthesis of highly functionalized quaternary imidazole derivatives via [3 + 2] heterocyclization, involving aryl migration and ring-opening of oxirane, has been developed. This dominoreaction enables the successful assembly of three new sigma bonds including two C–N bonds in a simple operation. Features of this strategy include the mild conditions, convenient operation