2-Ethoxy-3-pyridylboronic acid: a versatile reagent for the synthesis of highly-functionalised 3-aryl/heteroaryl-pyridines via Suzuki cross-coupling reactions

A mechanistic proposal for the protodeboronation of neat boronic acids: boronic acid mediated reaction in the solid state

“…3(B), identifies commonly occurring supramolecular structural features. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] Such compounds were prepared under similar conditions and so their yields can reasonably be compared. Hall stated that boronic acids regularly form these interactions in the solid state.…”

“…The yield of the compound leading to this crystal structure was compared to that of all other boronic acids described in the same paper. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] Such compounds were prepared under similar conditions and so their yields can reasonably be compared. It was found (see ESI †) that compounds which form crystal structures that satisfy the geometric requirements highlighted in Fig.…”

Optimization of the Suzuki coupling reaction in the synthesis of 2‐[(2‐substituted)phenyl]pyrrole derivatives

“…Nevertheless, there are examples of direct Suzuki coupling for preparation of biaryls and heteroaryls involving an unprotected NH 2 group [29][30][31][32][33][34][35]. However, to the best of our knowledge, an attempt to couple a pyrrole moiety to o-substituted anilines in a Pd-catalyzed reaction has not been reported.…”

Metalated Heterocycles in Organic Synthesis: Recent Applications

“…Thus, examples of the use of 3-pyridinboronic acids in the last years are common, 246 as it is the case of 2-ethoxy-3-pyridylboronic acid 126, obtained by a DoM reaction of 2-ethoxypyridine (125), which has been employed for the coupling reaction with heteroaryl bromides such as 5-bromo-2-methoxypyrimidine (127), to give the corresponding coupled product 128 (Scheme 38). 247 In addition, examples of the use 4-pyridylboronic acids for the preparation of 4,4'-bipyridyl systems can be recently found, 248 as well as the use of N-alkyl-boronopyridinium salts as thermally stable and reusable amide condensation catalysts. 249 …”