Full chirality transfer in the synthesis of hindered tertiary boronic esters under in situ lithiation–borylation conditions
作者:D. J. Blair、S. Zhong、M. J. Hesse、N. Zabaleta、E. L. Myers、V. K. Aggarwal
DOI:10.1039/c6cc00536e
日期:——
Using non-cryogenic lithiation-borylation, sterically hindered tertiary neopentyl glycol boronicesters can be prepared from secondary benzylic carbamates with full chirality transfer.
使用非低温锂化-硼酸化,可以从具有完全手性转移的仲苄基氨基甲酸酯制备位阻叔新戊二醇硼酸酯。
Full Chirality Transfer in the Conversion of Secondary Alcohols into Tertiary Boronic Esters and Alcohols Using Lithiation-Borylation Reactions
作者:Viktor Bagutski、Rosalind M. French、Varinder K. Aggarwal
DOI:10.1002/anie.201001371
日期:——
New conditions, full transfer: Using MgBr2/MeOH as an additive now provides essentially 100 % retention of configuration in the lithiation–borylation reaction, thus leading to tertiaryboronicesters (or tertiary alcohols) with exceptionally high ee values in all cases—even with rather hindered substrates and more stabilized lithiated carbamates (see scheme; Cb=carbamate, pin=OCMe2CMe2O).