97674-05-0Relevant academic research and scientific papers
Generation of (1-Alkoxycyclopropyl)lithium Reagents
Gadwood, Robert C.,Rubino, Mark R.,Nagarajan, Sridhar C.,Michel, Suzanne T.
, p. 3255 - 3260 (1985)
Various approaches to the generation of (1-alkoxycyclopropyl)lithium reagents were investigated.The syntheses of tri-n-butylstannane, cyclopropyl 2,4,6-triisopropylbenzoate, and 1-bromo-1-ethoxycyclopropane were carried out
Studies on the Lithiation, Borylation, and 1,2-Metalate Rearrangement of O-Cycloalkyl 2,4,6-Triisopropylbenzoates
Mykura, Rory C.,Songara, Pradip,Luc, Eugenia,Rogers, Jack,Stammers, Ellie,Aggarwal, Varinder K.
supporting information, p. 11436 - 11441 (2021/04/19)
A broad range of acyclic primary and secondary 2,4,6-triisopropylbenzoate (TIB) esters have been used in lithiation-borylation reactions, but cyclic TIB esters have not. We have studied the use of cyclic TIB esters in lithiation-borylation reactions and looked at the effect of ring size (3- → 6-membered rings) on the three key steps of the lithiation-borylation protocol: deprotonation, borylation and 1,2-metalate rearrangement. Although all rings sizes could be deprotonated, the cyclohexyl case was impractically slow, and the cyclopentyl example underwent α-elimination faster than deprotonation at ?78 °C and so could not be used. Both cyclobutyl and cyclopropyl cases underwent rapid borylation, but only the cyclobutyl substrate underwent 1,2-metalate rearrangement. Thus, the cyclobutyl TIB ester occupies a “Goldilocks zone,” being small enough for deprotonation and large enough to enable 1,2-migration. The generality of the reaction was explored with a broad range of boronic esters.
