{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,9,30]],"date-time":"2023-09-30T04:22:54Z","timestamp":1696047774041},"reference-count":16,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2005,4,11]],"date-time":"2005-04-11T00:00:00Z","timestamp":1113177600000},"content-version":"vor","delay-in-days":100,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chirality"],"published-print":{"date-parts":[[2005,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The performance of a catalyst used in asymmetric synthesis is likely to be dependent upon its stereoisomeric purity. An impurity was detectable by <jats:sup>31<\/jats:sup>P NMR in early development batches of the asymmetric hydrogenation catalyst [(<jats:italic>S<\/jats:italic>,<jats:italic>S<\/jats:italic>)\u2010Me\u2010BPE\u2010Rh(COD)]<jats:sup>+<\/jats:sup>BF<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-2.gif\" xlink:title=\"urn:x-wiley:08990042:media:CHIR20147:tex2gif-stack-2\" \/> made from the ligand bis((2<jats:italic>S<\/jats:italic>,5<jats:italic>S<\/jats:italic>)\u20102,5\u2010dimethylphospholano)ethane [(<jats:italic>S<\/jats:italic>,<jats:italic>S<\/jats:italic>)\u2010Me\u2010BPE]. Its identity as a stereoisomer with one chiral and one <jats:italic>meso<\/jats:italic>\u2010phospholane ring was deduced by comparison of the <jats:sup>31<\/jats:sup>P NMR spectra and GC traces of the ligand with a deliberately synthesized mixture of isomers. Interestingly, the impurity corresponded to a <jats:italic>trans<\/jats:italic>\u2010<jats:italic>meso<\/jats:italic> isomer formed by thermal (200\u00b0C) pyramidal inversion at phosphorus of the initially synthesized <jats:italic>cis<\/jats:italic>\u2010<jats:italic>meso<\/jats:italic>\u2010phospholane when the ligand was purified by distillation. Low levels of this <jats:italic>trans<\/jats:italic>\u2010<jats:italic>meso<\/jats:italic>\/chiral impurity do not significantly impair the enantioselectivity of the rhodium complex as an asymmetric hydrogenation catalyst, but high levels of stereochemical impurities resulted in a loss of both enantioselectivity and activity. Therefore it is indeed important to establish that a catalyst used in asymmetric catalysis is sufficiently stereoisomerically pure. Owing to strict control of the stereochemical purity of the key hexane\u20102,5\u2010diol intermediate, the impurity is not detected in production batches. <jats:italic>Chirality 17:177\u2013185, 2005.<\/jats:italic> \u00a9 2005 Wiley\u2010Liss, Inc.<\/jats:p>","DOI":"10.1002\/chir.20147","type":"journal-article","created":{"date-parts":[[2005,4,11]],"date-time":"2005-04-11T20:57:57Z","timestamp":1113253077000},"page":"177-185","source":"Crossref","is-referenced-by-count":1,"title":["Identifying stereoisomers of the asymmetric hydrogenation catalyst [Me\u2010BPE\u2010Rh(COD)]<sup>+<\/sup>BF"],"prefix":"10.1002","volume":"17","author":[{"given":"Martin E.","family":"Fox","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raymond","family":"McCague","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2005,4,11]]},"reference":[{"key":"e_1_2_1_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3773(20020617)41:12<1998::AID-ANIE1998>3.0.CO;2-8"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3773(20020617)41:12<2008::AID-ANIE2008>3.0.CO;2-4"},{"key":"e_1_2_1_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0926-860X(01)00801-8"},{"key":"e_1_2_1_5_2","first-page":"855","article-title":"Asymmetric hydrogenation of pharmaceutically interesting substrates","volume":"6","author":"Lennon IC","year":"2003","journal-title":"Curr Opin Drug Discovery Dev"},{"key":"e_1_2_1_6_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00075a031"},{"key":"e_1_2_1_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0957-4166(00)86109-1"},{"key":"e_1_2_1_8_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar990085c"},{"key":"e_1_2_1_9_2","unstructured":"BerensU. 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US Patent 6 545 183."},{"key":"e_1_2_1_9_3","first-page":"1","volume":"130","year":"1999","journal-title":"Chem Abstr"},{"key":"e_1_2_1_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo034397b"},{"key":"e_1_2_1_11_2","first-page":"397","article-title":"Choice of biocatalyst in the development of industrial biotransformations","author":"Taylor SJC","year":"2000","journal-title":"Stereoselect Biocatal"},{"key":"e_1_2_1_12_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00075a056"},{"key":"e_1_2_1_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/0957-4166(94)80028-6"},{"key":"e_1_2_1_14_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja034715o"},{"key":"e_1_2_1_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja048079l"},{"key":"e_1_2_1_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(01)01552-0"}],"container-title":["Chirality"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchir.20147","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chir.20147","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,29]],"date-time":"2023-09-29T06:09:54Z","timestamp":1695967794000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/chir.20147"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,1]]},"references-count":16,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2005,1]]}},"alternative-id":["10.1002\/chir.20147"],"URL":"https:\/\/doi.org\/10.1002\/chir.20147","archive":["Portico"],"relation":{},"ISSN":["0899-0042","1520-636X"],"issn-type":[{"value":"0899-0042","type":"print"},{"value":"1520-636X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2005,1]]}}}