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Lee D, Newman SG, Taylor MS. Boron-Catalyzed Direct Aldol Reactions of Pyruvic Acids. Org Lett 2009; 11:5486-9. [DOI: 10.1021/ol902322r] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Doris Lee
- Department of Chemistry, Lash Miller Laboratories, University of Toronto 80 St. George Street, Toronto ON M5S 3H6, Canada
| | - Stephen G. Newman
- Department of Chemistry, Lash Miller Laboratories, University of Toronto 80 St. George Street, Toronto ON M5S 3H6, Canada
| | - Mark S. Taylor
- Department of Chemistry, Lash Miller Laboratories, University of Toronto 80 St. George Street, Toronto ON M5S 3H6, Canada
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Kliegel W, Lubkowitz G, Pokriefke JO, Rettig SJ, Trotter J. Nitrones and oximes of bifunctional carbonyl compounds and their reaction products with diarylborinic acids. Crystal and molecular structure of examples of five-, six-, and seven-membered boron chelates. CAN J CHEM 2000. [DOI: 10.1139/v00-137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Synthesis has been carried out of diarylboron chelates of 2- and 3-hydroxynitrones, of 2- and 3-hydroxyoximes, and of 2-carboxynitrones and a 2-carboxyoxime. The structures have been determined from spectroscopic data and from X-ray analyses of 5d, 9a, 11b, and 19. Crystals (at 180 K) of 5d are monoclinic, a = 10.543(2), b = 19.085(4), c = 10.2667(3) Å, β = 90.4978(7)°, Z = 4, space group P21/c; those of 9a are orthorhombic, a = 10.9913(5), b = 14.9329(7), c = 10.2460(13) Å, Z = 4, space group P212121; those of 11b are monoclinic, a = 11.227(2), b = 9.967(2), c = 17.0537(4) Å, β = 105.4179(5)°, Z = 4, space group P21/n; those of 19 are monoclinic, a = 11.1847(15), b = 13.715(3), c = 11.5559(5) Å, β = 104.8730(10)°, Z = 4, space group P21/n. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R(F, I [Formula: see text] 3σ(I)) = 0.049, 0.047, 0.042, and 0.047, respectively, for CCD data for 5d, 9a, 11b, and 19. The four molecules contain five-, seven-, six-, and five-membered rings, respectively, with O-B-N groups in the 5d, 11b, and 19, and O-B-O in 9a; the rings exhibit various deviations from planarity, particularly the seven-membered ring.Key words: diarylboron chelates, hydroxyoximes, hydroxynitrones, carboxyoximes, carboxynitrones, organoboron compounds, crystal structure.
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