Synthesis of 3-(Hetero)aryl Tetrahydropyrazolo[3,4-c]pyridines by Suzuki–Miyaura Cross-Coupling Methodology

• DOI: 10.1021/jo5012015
• Publication Date: 2014-07-22T15:03:40Z
• Authors: Paul D. Kemmitt; Kevin Blades; Matthew R. Box; Stephanie Dickinson; Gillian M. Lamont; Katrina Madden; William McCoull; Jason Williams
• Keywords: Trifluoromethanesulfonate; Pyrazole; Suzuki reaction; Boronic acid

A new synthetic route to 3-(heteroaryl) tetrahydropyrazolo[3,4-c]pyridines has been developed that uses the Suzuki–Miyaura cross-coupling of a triflate 6 with (hetero)aryl boronic acids or esters. Using Pd(OAc)2 and XPhos an precatalyst, diverse range substituents at C3 position tetrahydropyrazolo[3,4-c]pyridine skeleton were prepared. The use pivaloyloxymethyl benzyl protection also offers potential differentially functionalize pyrazole tetrahydropyridine nitrogens.