Mechanistic details of the 2+2 photocycloaddition

CHED 438

Alex Parent, aap32@email.byu.edu and Steven A. Fleming, steve_fleming@byu.edu. Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602
Recent research in the area of organic photochemistry has increased our understanding of the regio- and stereoselectivity of [2+2] photocycloadditions which result in the formation of 4-member rings. Our work has addressed the possible reasons for the observed selectivity in aryl-substituted [2+2] cycloadditions. Results suggest that pi-pi interactions account for the selectivity. It also appears that radical stabilization of potential intermediates may control the reaction. We will discuss the synthesis and photoreactivity of silyl tethered alkenes that answer the mechanistic questions that have been raised.