The palladium-catalyzed, two-step, one-potborylation/Suzuki coupling (BSC) reaction was developed to synthesize sterically hindered 2,2'-disubstituted biphenyl and phenyl-indole compounds in a short, simple, and efficient manner from two easily accessible aryl halides. High yields can be obtained by choosing properly both components according to their rough electronic properties. The illustration
The atropisomeric enantiomers of 7-, 8-, and 9-membered-ring dibenzolactams were separated by using chiral HPLC, and their stereochemistries were clarified by using X-ray crystallographic analysis. The atropisomers showed high stereochemical stability with the 8-membered ring being the most stable. In 7- and 8-membered dibenzolactams, highly stereoselective C7-methylation proceeded from the lower side
Crystallization-Induced Dynamic Resolution toward the Synthesis of (<i>S</i>)-7-Amino-5<i>H</i>,7<i>H</i>-dibenzo[<i>b</i>,<i>d</i>]-azepin-6-one: An Important Scaffold for γ-Secretase Inhibitors
作者:Sukhen Karmakar、Vijay Byri、Ashvinikumar V. Gavai、Richard Rampulla、Arvind Mathur、Anuradha Gupta
DOI:10.1021/acs.oprd.6b00207
日期:2016.10.21
An enantioselective synthesis of (S)-7-amino-5H,7H-dibenzo[b,d]azepin-6-one (S-1) is described. The key step in the sequence involved crystallization-induced dynamic resolution (CIDR) of compound 7 using Boc-D-phenylalanine as a chiral resolving agent and 3,5-dichlorosalicylaldehyde as a racemization catalyst to afford S-1 in 81% overall yield with 98.5% enantiomeric excess.
Atropisomeric Properties of the Dibenzo[<i>b</i>,<i>d</i>]azepin-6-one Nucleus
Dibenzo[b,d]azepin-6-ones (2a,b) were separated by chiral HPLC into the aR- and aS-atropisomers with high stereochemical stability, and methylation at C7 of 2a stereoselectively gave the (aR*,7R*) isomer (4a), which converted to the thermodynamically stable (aS*,7R*) atropisomer (5a) after heating.