Theoretical study of stereoselectivity of the [1 + 2] cycloaddition reaction between (1S,3R,8S)-2,2-dichloro-3,7,7,10-tetramethyltricyclo[6,4,0,01.3]dodec-9-ene and dibromocarbene using density functional theory (DFT) B3LYP/6-31G*(d)

In this work we used density functional theory (DFT) B3LYP/6-31G*(d) to study the stoichiometric reaction between the product (1S,3R,8S)-2,2-dichloro-3,7,7,10-tetramethyltricyclo[6,4,0,01.3]dodec-9-ene (referred to here as P1) and dibromocarbene. We have shown that P1 behaves as a nucleophile, while dibromocarbene behaves as an electrophile; that the chemical potential of dibromocarbene is superior to that of P1 in absolute terms; and that P1 reacts with an equivalent quantity of dibromocarbene to produce two products: (1S,3R,8R,9S,11R)-10,10-dibromo-2,2-dichloro-3,7,7,11-tetramethyltetracyclo[6,5,0,01.3,09.11] tridecane (referred to here as P2) and (1S,3R,8R,9R,11S)-10,10-dibromo-2,2-dichloro-3,7,7,11-tetramethyltetracyclo[6,5,0,01.3,09.11] tridecane (referred to here as P3). P2 and P3 are formed at the α and β sides, respectively, of the C2 = C3 double bond of P1. This reaction is exothermic, stereoselective and chemospecific, and is controlled by charge transfer. Regioselectivity of the reaction was interpreted using the Lee-Yang-Parr functional.