Diels-Alder reactions of pinacol alkenylboronates: an experimental and theoretical study

VALLEJOS, M. M.; GRIMBLAT, N.; PELLEGRINET, S. C.

RSC Advances

Royal Society of Chemistry

Año: 2014 vol. 4 p. 36385 - 36400

2046-2069

We have studied the Diels-Alder reactions of pinacol alkenylboronates with cyclopentadiene under two different conditions: thermal heating at 170 °C in a pressure tube and with catalytic TFA (5 mol%) at 80 °C. Yields varied significantly from system to system and also for the uncatalyzed and catalyzed methodologies. Moderate to excellent exo-stereoselectivities were obtained in all cases. The theoretical study of the thermal reactions shed some light into the intriguing substituent effects observed experimentally. A variety of substituted 5-norbornen-2-ols were easily generated by subsequent in-situ oxidation of the cycloadducts with alkaline hydrogen peroxide.