Borylation of dienes

Identifier:  TFG:1207

Handle: https://hdl.handle.net/20.500.11797/TFG1207

Authors:  Sans Panadés, Ester

Abstract:
In 1993, Miyaura and his co-workers were the pioneers in promoting a metallic complex as a catalyst in the borylation reaction of terminal and internal alkynes with bis(pinacolato) diboron (B2pin2). The C-B bond can be modified in orders to achieve C-O, C-N, C-C bonds. The main point of the reaction is the activation of the diboron reactive. Oxidative addition is the most explored activation. Later investigations have developed other activations via σ-bond metathesis or transition metal-free catalysis. Moreover, the reactivity of different activated alkenes has been studied. The present study focuses on the third mentioned via, the transition metal-free catalysis. Earlier publications have shown the efficiency of activating the diboron reactive through an acid-base reaction with a base and methanol. As this via is good in other substrates, it has been thought that the reactivity with a new substrate, the dienes, may be investigated. The diboron reactive activation is produced by the addition of metoxy grup in it. This process produces the quaternization of one moiety of boron and the pinacolboryl moiety becomes nucleophile enough to attack the diene. The study has been developed with four dienes: 1,3-cyclohexediene, 1,3-cycloheptediene, 1,3-cyclooctadiene and α-phellendrene. The main diboron reactive is B2pin2. A study has been elaborated about the different parameters which could improve the yields and the selectivity of each reaction: the temperature, the base type, the dissolvent type, the limited reactive and the numbers of equivalents in the excess reactive.