Prieto, Monica published the artcileArylboronic acids and arylpinacolboronate esters in Suzuki coupling reactions involving indoles. Partner role swapping and heterocycle protection, HPLC of Formula: 642494-36-8, the publication is Journal of Organic Chemistry (2004), 69(20), 6812-6820, database is CAplus and MEDLINE.
Yields of Suzuki couplings involving indoles depended upon (i) whether arylboronic acids or arylpinacolboronate esters were used, (ii) whether the heterocycle was the aryl halide or the arylboron coupling partner, and (iii) whether the heterocycle was protected or not. Highest yields, which were unaffected by incorporating Boc or Tos protection at the heterocyclic nitrogen, were obtained when indole bromides were reacted with phenylboronic acids. When indolylboronic acids were reacted with Ph bromides, yields were somewhat lower and depended on the nitrogen substituent, being highest in the absence of protection, lower in the presence of the Boc group, and lowest of all with the Tos group. Arylpinacolboronate esters were less reactive than arylboronic acids. They required considerably longer reaction times and furnished generally lower yields of biaryl, e.g., I. Furthermore, irresp. of whether the heterocycle was the aryl bromide or the arylpinacolboronate ester, these yields were highest when it was protected with the Tos group. Yields were lower with the Boc group, and unprotected heterocycles gave only traces of biaryl. Careful selection of arylboron reagent, of coupling partner roles, and of protecting groups were essential to ensuring optimum results in these Suzuki couplings.
Journal of Organic Chemistry published new progress about 642494-36-8. 642494-36-8 belongs to indole-building-block, auxiliary class Indole,Boronic acid and ester,Indole,Boronate Esters,Boronic acid and ester, name is 6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole, and the molecular formula is C14H18BNO2, HPLC of Formula: 642494-36-8.
Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles