Erste asymmetrische Synthese β-binaphthylgestuetzter Silane, Stannane und Borane

Article abstract of DOI:10.1016/0022-328X(88)80180-3

Starting with differently metallated 2,2'-dimethyl-1,1'-binaphthyls, various synthetic approaches to dihydrodinaphthoborepines (2) were attempted.As the borylation of the open chain derivetives (4a, b) did not succeed under cyclization, the (R)-dihydronaphthosilepine (5a) and the (R)- and (s)-dihydrodinaphthostannepines (7a) were prepared first, by starting from the enantiomerically pure bisbenzyllithium compounds (4a).The reaction of 5a with boron tribromide and of 7a with dichloroethylborane led exclusively to a halogen-methyl exchange reaction, to give the bromodihydrosilepine (5b) and the chlorodihydrostannepine (7b), while reaction of 7a with trichloroborane predominantly led to the formation of chlorodihydroborepine (2a).