Divergent reactivity of nucleophilic 1-bora-7a-azaindenide anions

摘要: The reactions of 1-bora-7a-azaindenide anions, prepared in moderate to excellent yields by reduction the appropriate 1-bora-7a-azaindenyl chlorides with KC8 THF, alkyl halides and carbon dioxide were studied. With (CH2Cl2, CH3I BrCH(D)CH(D)tBu), anions behave as boron alkylating centre via a classic SN2 mechanism. This was established DFT methods experiments utilizing neo-hexyl stereoprobe BrCH(D)CH(D)tBu. These part driven re-aromatization six membered pyridyl ring upon formation product. Conversely, reaction CO2, novel carboxylation C-2 alpha observed. Computations indicated that while kinetically feasible, products B-carboxylation not thermodynamically favored relative observed carboxylated species, which formed preferably due generation both C–C B–O bonds. In these products, remains non-aromatic, accounting for reversibility carboxylation.