Use of alkyl 2,4,6-triisopropylbenzoates in the asymmetric homologation of challenging boronic esters
作者:Robin Larouche-Gauthier、Catherine J. Fletcher、Irantzu Couto、Varinder K. Aggarwal
DOI:10.1039/c1cc14469c
日期:——
(-)-Sparteine induced lithiation of primary 2,4,6-triisopropylbenzoates and subsequent homologation of boronicesters is reported. A comparative study with lithiated N,N-diisopropylcarbamates has demonstrated the superiority of the hindered benzoate.
Stereoselective Total Synthesis of (+)-Giganin and Its C10 Epimer by Using Late-Stage Lithiation-Borylation Methodology
作者:Catherine J. Fletcher、Katherine M. P. Wheelhouse、Varinder K. Aggarwal
DOI:10.1002/anie.201208403
日期:2013.2.25
The first totalsynthesis of (+)‐giganin and its unnatural diastereoisomer (+)‐C10‐epi‐giganin has been completed in a total of 13 linear steps, and 7 % and 8 % overall yield, respectively (see scheme; (‐)‐sp= (‐)‐sparteine, (+)‐sps=(+)‐sparteine surrogate). Lithiation–borylationmethodology has been successfully applied in the key step, to couple together advanced intermediates with very high diastereoselectivity
Asymmetric Synthesis of Allylsilanes by the Borylation of Lithiated Carbamates: Formal Total Synthesis of (−)-Decarestrictine D
作者:Michael Binanzer、Guang Yu Fang、Varinder K. Aggarwal
DOI:10.1002/anie.201001223
日期:——
carbamates react with retention of configuration, thereby providing enantio‐complementary routes to β‐hydroxy allylsilanes (see scheme). The methodology has been applied in a concise formal totalsynthesis of (−)‐decarestrictineD.
Synthesis of Highly Enantioenriched C-Tertiary Amines From Boronic Esters: Application to the Synthesis of Igmesine
作者:Viktor Bagutski、Tim G. Elford、Varinder K. Aggarwal
DOI:10.1002/anie.201006037
日期:2011.2.1
Better than all the rest: Tertiaryboronicesters, readily available using the lithiation–borylation reaction, have been converted into tertiary alkylamines in very high ee. The work has been applied to a short, modular, and fully stereocontrolled synthesis of the pharmaceutical igmesine and chiral 2,2‐disubstituted piperidines.