{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,8]],"date-time":"2026-03-08T20:51:38Z","timestamp":1773003098051,"version":"3.50.1"},"reference-count":18,"publisher":"Wiley","issue":"39","license":[{"start":{"date-parts":[[2003,9,23]],"date-time":"2003-09-23T00:00:00Z","timestamp":1064275200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Angew Chem Int Ed"],"published-print":{"date-parts":[[2003,10,13]]},"DOI":"10.1002\/anie.200351591","type":"journal-article","created":{"date-parts":[[2003,10,10]],"date-time":"2003-10-10T23:09:05Z","timestamp":1065827345000},"page":"4771-4774","source":"Crossref","is-referenced-by-count":72,"title":["Asymmetric Hetero\u2010Ene Reactions of Trimethylsilyl Enol Ethers Catalyzed by Tridentate Schiff Base Chromium(<scp>III<\/scp>) Complexes"],"prefix":"10.1002","volume":"42","author":[{"given":"Rebecca T.","family":"Ruck","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eric N.","family":"Jacobsen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2003,10,8]]},"reference":[{"key":"e_1_2_2_1_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja025588j"},{"key":"e_1_2_2_2_2","unstructured":"The hetero\u2010Diels\u2013Alder reactions reported using a similar catalyst also appear to proceed by a concerted mechanism:"},{"key":"e_1_2_2_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1521-3757(19990816)111:16<2549::AID-ANGE2549>3.0.CO;2-H"},{"key":"e_1_2_2_3_3","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1521-3773(19990816)38:16<2398::AID-ANIE2398>3.0.CO;2-E"},{"key":"e_1_2_2_4_2","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3757(20020816)114:16<3185::AID-ANGE3185>3.0.CO;2-S"},{"key":"e_1_2_2_4_3","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3773(20020816)41:16<3059::AID-ANIE3059>3.0.CO;2-I"},{"key":"e_1_2_2_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(96)02376-3"},{"key":"e_1_2_2_6_2","unstructured":"The procedure for the preparation of catalysts1\u20133[1]incorporates a late\u2010stage workup step with HCl which is the likely source of acidic impurities."},{"key":"e_1_2_2_7_2","doi-asserted-by":"publisher","DOI":"10.1021\/ol006976y"},{"key":"e_1_2_2_8_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja016893s"},{"key":"e_1_2_2_9_2","unstructured":"The crude \u03b2\u2010hydroxytrimethylsilyl enol ether products listed in Table 1 were characterized by1H NMR spectroscopy; the purified \u03b2\u2010hydroxyketone hydrolysis products were fully characterized."},{"key":"e_1_2_2_10_2","unstructured":"Separation of the products from the nonpolar catalyst was difficult and required careful chromatography. The low recovery of the silyl enol ether products is attributable to partial hydrolysis due to prolonged exposure to the chromatographic support."},{"key":"e_1_2_2_11_2","unstructured":"The unprotected \u03b2\u2010hydroxy silyl enol ethers underwent competitive elimination and\/or hydrolysis reactions under a variety of Lewis acid catalyzed conditions."},{"key":"e_1_2_2_12_2","unstructured":"The stereochemical assignment is tentative and based on closely related reactions:"},{"key":"e_1_2_2_13_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo962417m"},{"key":"e_1_2_2_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/0040-4039(96)01962-4"},{"key":"e_1_2_2_15_2","unstructured":"Electron\u2010deficient benzaldehyde derivatives bearingorthosubstituents provided the best rates and enantioselectivities in this reaction similar to observations made in ene reactions with 2\u2010methoxypropene. See ref. [1]."},{"key":"e_1_2_2_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4020(98)00493-1"}],"container-title":["Angewandte Chemie International Edition"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fanie.200351591","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/anie.200351591","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,11]],"date-time":"2023-10-11T06:00:14Z","timestamp":1697004014000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/anie.200351591"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2003,10,8]]},"references-count":18,"journal-issue":{"issue":"39","published-print":{"date-parts":[[2003,10,13]]}},"alternative-id":["10.1002\/anie.200351591"],"URL":"https:\/\/doi.org\/10.1002\/anie.200351591","archive":["Portico"],"relation":{},"ISSN":["1433-7851","1521-3773"],"issn-type":[{"value":"1433-7851","type":"print"},{"value":"1521-3773","type":"electronic"}],"subject":[],"published":{"date-parts":[[2003,10,8]]}}}