ja046429y_si_001.pdf (1.62 MB)
Dramatic Effects of Boryl Substituents on Thermal Ring-Closing Reaction of Vinylallenes
journal contribution
posted on 2004-09-08, 00:00 authored by Masahiro Murakami, Shinji Ashida, Takanori MatsudaThe unidirectional thermal ring-closing reaction of cis-4-phenyl-5-borylpenta-1,2,4-triene giving 4-boryl-3-methylene-1-phenylcyclobutene proceeded significantly faster than that of the trans-isomer. The large rate difference between the cis- and trans-stereoisomers is ascribed to electronic participation of the vacant boron p orbital in the transition state SHOMO.