Selective amidation of 2,6-dihalogenopurines: application to the synthesis of new 2,6,9-trisubstituted purines.
We report herein the palladium(0)/Xantphos-catalyzed cross-coupling of various amides with 2,6-dihalogenopurines, with substituent-dependent regioselectivity. Furthermore, subjecting the same 2,6-dihalogenopurines to SNAr conditions with amide/NaH in DMF leads to inverted regioselectivity albeit in lower yield. These methodologies allow the two-step synthesis of new 2,6,9-trisubstituted purines from readily available 2,6-dihalogenopurines.
Piguel
Sandrine
S
Univ Paris-Sud, Orsay F-91405, France.
Legraverend
Michel
M
D000586:Amination; D002384:Catalysis; D006219:Halogens / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D011687:Purines / Q000138:chemical synthesis / Q000737:chemistry*
D006219:Halogens; D011687:Purines; D010165:Palladium