Catalytic reduction of carbon dioxide at carbon electrodes modified with cobalt phthalocyanine

(1 1) There may be a question that the bad interactions depicted in 9 and 16 can be avoided by rotating the carbon so that the hydrogen is in the position of the methyl in 9 and the phenyl in 16. Inspection with a Dreiding model clearly indicates that such conformations are destabilized by the steric repulsion between the 9-BBN ring and the phenyl group in 9 and between the 9-BBN ring and the methyl group in 16. (12) (a) For addition of allylboronates to Schiff bases, see: Hoffmann, R. W.; Eichler, G.; Endesfelder, A. Liebigs Ann. Chem. 1983,2000. (b) When alkylorganometallics, such as BuCu-BF, and Bu2CuLi.BF,, were utilized, the Cram/anti-Cram selectivity was low (-4:l). This is reasonable since the six-membered cyclic transition state is not involved in this reaction. For the reaction of imines with RCuaBF,, see: Wada, M.; Sakurai, Y. ; Akiba, K . Tetrahedron Lett. 1984, 25, 1079. If (13) An oxonium salt of aldehydes may take a trans geometry (17).