TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES
Acid promoted cyclisation of homochiral (R)-N-(3,4-dimethoxyphenethyl)-halostachine proceeds with almost total racemisation to yield 1-phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine (e.e. 6%). Coordination of the cyclisation precursor to the tricarbonylchromium(0) moiety renders the cyclisation co...
| Main Authors: | , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
1990
|
| _version_ | 1797076732136652800 |
|---|---|
| author | Coote, S Davies, S Middlemiss, D Naylor, A |
| author_facet | Coote, S Davies, S Middlemiss, D Naylor, A |
| author_sort | Coote, S |
| collection | OXFORD |
| description | Acid promoted cyclisation of homochiral (R)-N-(3,4-dimethoxyphenethyl)-halostachine proceeds with almost total racemisation to yield 1-phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine (e.e. 6%). Coordination of the cyclisation precursor to the tricarbonylchromium(0) moiety renders the cyclisation completely stereospecific to afford, after decomplexation, homochiral (+)-(R)-1 -phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine. (-)-(1R,2S)-N-(3,4-Dimethoxyphenethyl)ephedrine undergoes acid mediated cyclisation to furnish trans-(-)-(1R,2S)-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine as a single diastereoisomer. In contrast, the epimeric cyclisation precursor (-)-(1R,2R)-N-(3,4-dimethoxyphenethyl)pseudoephedrine cyclises to give a mixture (ratio 91:9) of trans- and cis-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine. However, cyclisation of the tricarbonylchromium(0) complex of(-)-(1R,2R)-N-(3,4-dimethoxyphenethyl)pseudo-ephedrine is completely stercoselective to yield trans-(+)-(1S,2R)-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine after decomplexation. © 1991. |
| first_indexed | 2024-03-07T00:07:57Z |
| format | Journal article |
| id | oxford-uuid:783438b6-2431-42e9-975f-66d27fe93bec |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:07:57Z |
| publishDate | 1990 |
| record_format | dspace |
| spelling | oxford-uuid:783438b6-2431-42e9-975f-66d27fe93bec2022-03-26T20:29:09ZTRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINESJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:783438b6-2431-42e9-975f-66d27fe93becEnglishSymplectic Elements at Oxford1990Coote, SDavies, SMiddlemiss, DNaylor, AAcid promoted cyclisation of homochiral (R)-N-(3,4-dimethoxyphenethyl)-halostachine proceeds with almost total racemisation to yield 1-phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine (e.e. 6%). Coordination of the cyclisation precursor to the tricarbonylchromium(0) moiety renders the cyclisation completely stereospecific to afford, after decomplexation, homochiral (+)-(R)-1 -phenyl-N-methyl-1,2,4,5-tetrahydrobenz[d]azepine. (-)-(1R,2S)-N-(3,4-Dimethoxyphenethyl)ephedrine undergoes acid mediated cyclisation to furnish trans-(-)-(1R,2S)-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine as a single diastereoisomer. In contrast, the epimeric cyclisation precursor (-)-(1R,2R)-N-(3,4-dimethoxyphenethyl)pseudoephedrine cyclises to give a mixture (ratio 91:9) of trans- and cis-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine. However, cyclisation of the tricarbonylchromium(0) complex of(-)-(1R,2R)-N-(3,4-dimethoxyphenethyl)pseudo-ephedrine is completely stercoselective to yield trans-(+)-(1S,2R)-1-phenyl-2-methyl-N-methyl-7,8-dimethoxy tetrahydrobenzazepine after decomplexation. © 1991. |
| spellingShingle | Coote, S Davies, S Middlemiss, D Naylor, A TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES |
| title | TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES |
| title_full | TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES |
| title_fullStr | TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES |
| title_full_unstemmed | TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES |
| title_short | TRICARBONYLCHROMIUM(0) PROMOTED STEREOSELECTIVE CYCLIZATIONS OF THE N-3,4-DIMETHOXYPHENETHYL DERIVATIVES OF THE 1-PHENYL ETHANOLAMINES HALOSTACHINE, EPHEDRINE AND PSEUDOEPHEDRINE TO 1-PHENYL-N-METHYL-7,8-DIMETHOXY-1,2,4,5-TETRAHYDROBENZAZEPINES |
| title_sort | tricarbonylchromium 0 promoted stereoselective cyclizations of the n 3 4 dimethoxyphenethyl derivatives of the 1 phenyl ethanolamines halostachine ephedrine and pseudoephedrine to 1 phenyl n methyl 7 8 dimethoxy 1 2 4 5 tetrahydrobenzazepines |
| work_keys_str_mv | AT cootes tricarbonylchromium0promotedstereoselectivecyclizationsofthen34dimethoxyphenethylderivativesofthe1phenylethanolamineshalostachineephedrineandpseudoephedrineto1phenylnmethyl78dimethoxy1245tetrahydrobenzazepines AT daviess tricarbonylchromium0promotedstereoselectivecyclizationsofthen34dimethoxyphenethylderivativesofthe1phenylethanolamineshalostachineephedrineandpseudoephedrineto1phenylnmethyl78dimethoxy1245tetrahydrobenzazepines AT middlemissd tricarbonylchromium0promotedstereoselectivecyclizationsofthen34dimethoxyphenethylderivativesofthe1phenylethanolamineshalostachineephedrineandpseudoephedrineto1phenylnmethyl78dimethoxy1245tetrahydrobenzazepines AT naylora tricarbonylchromium0promotedstereoselectivecyclizationsofthen34dimethoxyphenethylderivativesofthe1phenylethanolamineshalostachineephedrineandpseudoephedrineto1phenylnmethyl78dimethoxy1245tetrahydrobenzazepines |