DFT Studies of Dimerization Reactions of Boroles

• Published in: Chemistry : a European journal Vol. 23; no. 48; pp. 11587 - 11597
• Main Authors: Wang, Zheng, Zhou, Yu, Lee, Ka‐Ho, Lam, Wai Han, Dewhurst, Rian D., Braunschweig, Holger, Marder, Todd B., Lin, Zhenyang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 25.08.2017
• Subjects: Accessibility; Aromatic compounds; boroles; Boron; Butadiene; Chemistry; density functional calculations; Diels–Alder; Dimerization; dimerization reactions; Dimers; reaction mechanism; density functional calculations; dimerization reactions; Diels-Alder; reaction mechanism; boroles
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201701737

Boroles undergo dimerization reactions to give Diels–Alder (DA) dimers, bridged‐bicyclic (BB) dimers or spiro dimers (SD) depending on the substituents on the borole. We performed DFT calculations to investigate how different substituents at the carbon atoms of the butadiene backbone as well as at the boron atom influence the dimerization reaction pathways. The DFT results show that, in general, both the DA and BB dimers are easily accessible kinetically, and the DA dimers are thermodynamically more stable than the BB dimers. When the substituent–substituent repulsive steric interactions are alleviated to a certain extent, the BB dimers are more stable than the DA dimer, and become accessible. The SD dimers are generally kinetically difficult to obtain. However, we found that aryl substituents promote the formation of the SD dimers. Boroles undergo dimerization reactions to give Diels–Alder (DA) dimers, bridged‐bicyclic (BB) dimers or spiro dimers (SD) depending on the substituents on the borole. DFT calculations were performed to investigate how different substituents at the carbon atoms of the butadiene backbone as well as at the boron atom influence the dimerization reaction pathways.