Synthesis of enantioenriched tertiary boronic esters by the lithiation/borylation of secondary alkyl benzoates

…, DJ Blair, E Torres, VK Aggarwal

Index: Pulis, Alexander P.; Blair, Daniel J.; Torres, Eva; Aggarwal, Varinder K. Journal of the American Chemical Society, 2013 , vol. 135, # 43 p. 16054 - 16057

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Citation Number: 26

Abstract

Simple, secondary 2, 4, 6-triisopropyl benzoates (TIB esters) and secondary dialkyl N, N- diisopropyl carbamates have been reported to be resistant to deprotonation by strong bases. We have found that the combination of s BuLi (1.6 equiv) and TMEDA (6 equiv) in CPME at− 60° C enables deprotonation of unactivated secondary dialkyl TIB esters, but not the carbamates. These carbanions were reacted with a range of neopentyl boronic esters ...