Unexpected switch in regioselectivity of tether-directed Bingel-type biscyclopropanations depending on the leaving groups at tethered active methylene moietiesThis paper is dedicated to Emeritus Professor Soichi Misumi on the occasion of his 77th birthday. Electronic supplementary information (ESI) available: NMR, IR, UV/Vis and mass spectroscopies of t-2a and e-2a. See http://www.rsc.org/suppdata/cc/b2/b211337f/

The regioselectivity of tether-directed Bingel-type biscyclopropanations of [60]fullerene was switched depending on the leaving groups at tethered active methylene moieties; the reactions of [60]fullerene with unhalogenated tethered bis(active methylene) derivatives/I2 and with brominated derivatives in the presence of 1,7-diazabicyclo[5.4.0]undec-7-ene gave trans-4-adducts predominantly, while the reactions with chlorinated derivatives afforded equatorial-adducts almost exclusively.