α-Amidoboronate esters by amide-directed alkane C H borylation
摘要:
alpha-Amidoboronic acids have received significant attention in recent years following the development of Bortezomib as an FDA-approved treatment of multiple myeloma and mantle cell lymphoma. More versatile methods to access alpha-amidoboronic acids continue to be developed. A direct method to access the precursors, alpha-amidoboronate esters, by iridium-catalyzed C-H borylation of amides was developed using a readily available ligand/catalyst combination. Although the scope is limited, good yields of alpha-amidoboronate esters are achieved in high selectivity. Conversion of the boronate esters to the corresponding alpha-amidoboronic acids was also demonstrated. (C) 2019 Elsevier Ltd. All rights reserved.
DirectC(sp(3))-Hborylation of amides, ureas, and 2-aminopyridine derivatives at the position α to the N atom, which gives the corresponding α-aminoalkylboronates, has been achieved with a heterogeneous catalyst system consisting of [Rh(OMe)(cod)]2 and a silica-supported triarylphosphine ligand (Silica-TRIP) that features an immobilized triptycene-type cage structure with a bridgehead P atom. The