Facile ring-opening of THF at a lithium center induced by a pendant Si-H bond and BPh3Electronic supplementary information (ESI) available: Description of compounds 1-5 and 7. CCDC 1544769 (3) and 1544770 (7). For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt01671a

The macrocyclic polyamine 1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane [LH = (Me 3 TACD)H] formed adducts with tetramethyl-silazides [M{N(SiHMe 2 ) 2 }] (M = Li, Na, K) of light alkali metals. Upon heating, intramolecular dehydrocoupling occurred to give [M{(L)SiMe 2 N(SiHMe 2 )}]. BPh 3 induced facile ring-opening of THF when reacted with [Li{(L)SiMe 2 N(SiHMe 2 )}]. Triphenylborane (BPh 3 ) induces a facile THF ring-opening at a lithium center where a pendant Si-H bond acts as the nucleophile to cleave the C α -O bond.