Asymmetric synthesis of Sedum alkaloids via lithium amide conjugate addition
作者:Stephen G. Davies、Ai M. Fletcher、Paul M. Roberts、Andrew D. Smith
DOI:10.1016/j.tet.2009.09.104
日期:2009.12
Conjugateaddition of lithium (R)-N-allyl-N-(α-methylbenzyl)amide or lithium (R)-N-but-3-enyl-N-(α-methylbenzyl)amide to an alkyl hexa-2,4-dienoate or alkyl hepta-2,6-dienoate, followed by ring-closing metathesis of the olefin functionalities within the resultant β-amino ester, generates a range of diastereoisomerically pure azacycles in good yield. These homochiral templates are readily transformed
Catalytic Asymmetric Additions of Enol Silanes to In Situ Generated Cyclic, Aliphatic
<i>N</i>
‐Acyliminium Ions
作者:Oleg Grossmann、Rajat Maji、Miles H. Aukland、Sunggi Lee、Benjamin List
DOI:10.1002/anie.202115036
日期:2022.2.21
Saturated nitrogen heterocycles are essential pharmacophores in drugs and natural products, and general methods for their enantioselective synthesis are still highly sought after. A new direct approach utilizing hemiaminal methyl ethers as N-acyliminium precursors for the enantioselective preparation of cyclic, aliphatic and 2-subsituted pyrrolidines, piperidines and azepanes has been achieved.