Synthesis of Fmoc-protected (S)-3,5-dibromophenylalanine in presence of a phase transfer catalyst or a chiral catalyst was written by Wang, Qinting;Zhao, Shuai;Jin, Lei;Chen, Xin. And the article was included in Youji Huaxue in 2016.Name: (1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide This article mentions the following:
Two methods of catalytic asym. synthesis of (S)-3,5-dibromophenylalanine were presented. One approach was to use asym. alkylation reaction starting from diphenylimine glycine tert-Bu ester and 3,5-dibromobenzyl bromide, with O-allyl-N-9-anthracene Me bromide cinchonidine as phase-transfer catalyst, and the (S)-3,5-dibromophenylalanine derivative was obtained (up to 94.9% ee). The optimized conditions of asym. phase transfer catalytic alkylation were explored. Another method was to employ asym. hydrogenation starting from 2-acetylamino-3-(3,5-dibromophenyl) acrylic acid with bis(1,5-cyclooctadiene)rhodium trifluoromethanesulfonate and (R)-diphenylphosphino-N-methyl-1-[(S)-2-diphenyl-phosphinoferrocenyl]ethylamine [(R)-Me BoPhoz] as chiral catalyst. (S)-3,5-Dibromophenylalanine hydrochloride was obtained after hydrolysis. By Fmoc protection, Fmoc-(S)-3,5-dibromophenylalanine was obtained (up to 94.7% ee). By comparison of the two methods, the first one gives higher overall yield and a little bit better selectivity, and is more suitable for the synthesis of other chiral dihalo-substituent phenylalanine derivatives In the experiment, the researchers used many compounds, for example, (1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide (cas: 200132-54-3Name: (1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide).
(1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide (cas: 200132-54-3) belongs to quinuclidine derivatives. Quinuclidine exists in a number of naturally occurring compounds, biologically active agents, and privileged catalysts and ligands for asymmetric catalysis. Quinuclidine derivatives can also be formed conveniently by introducing substituents into the quinuclidine ring, but the scope of this method is rather limited by the available source of starting materials.Name: (1S,2S,4S,5R)-2-((R)-(Allyloxy)(quinolin-4-yl)methyl)-1-(anthracen-9-ylmethyl)-5-vinylquinuclidin-1-ium bromide
Referemce:
Quinuclidine – Wikipedia,
Quinuclidine | C7H13N | ChemSpider