Fine-tuning of boron complexes with cage-shaped ligand geometry: Rational design of triphenolic ligand as a template for structure control

Organic Letters

Volumn 10, Issue 5, 2008, Pages 929-932

  Yasuda, Makoto ^a   Yoshioka, Sachiko ^a   Nakajima, Hideto ^a   Chiba, Kouji ^b   Baba, Akio ^a  

^a OSAKA UNIVERSITY   (Japan)

^b JAPAN SCIENCE AND TECHNOLOGY AGENCY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 58149179923     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol7030944     Document Type: Article

References (18)

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5. Although we previously proposed the concept to explain the different characters between open- and cage-shaped borates, theoretical discussion had not been employed: Yasuda, M.; Yoshioka, S.; Yamasaki, S.; Somyo, T.; Chiba, K.; Baba, A. Org. Lett. 2006, 8, 761-764.
6. Similar cage-shaped compounds were reported as follows. As a Lewis base: Dinger, M. B.; Scott, M. J. Inorg. Chem. 2001, 40, 856-864.
7. As a titanium complex: Akagi, F.; Matsuo, T.; Kawaguchi, H. J. Am. Chem. Soc. 2005, 127, 11936-11937.
8. The described MOs are the lowest unoccupied orbitals with suitable lobes on boron as a Lewis acid. (5) Godard, A.; Robin, Y.; Queguiner, G. J. Organomet. Chem. 1987, 336, 1 - 12.
9. Recent review of ligands bearing phenoxy moieties: Matsuo, T.; Kawaguchi, H. Chem. Lett. 2004, 33, 640-645.
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11. Verkerk, U.; Fujita, M.; Dzwiniel, T. L.; McDonald, R.; Stryker, J. M. J. Am. Chem. Soc. 2002, 124, 9988-9989.
12. Fujita, M.; Qi, G.; Verkerk, U. H.; Dzwiniel, T. L.; McDonald, R.; Stryker, J. M. Org. Lett. 2004, 6, 2653 -2656.
13. The X-ray crystallographic data of 3aB-Py, 3bB-Py, 1B 8, and 3aB 8 are given in the Supporting Information.
14. Although pyridine shifts were observed, the anisotropic effect due to phenyl rings would confuse the estimates by NMR shifts. (10) (a) Yasuda, M.; Yamasaki, S.; Onishi, Y.; Baba, A. J. Am. Chem. Soc. 2004, 126, 7186-7187.
15. (a)Yasuda, M.; Yamasaki, S.; Onishi, Y.; Baba, A. J. Am. Chem. Soc. 2004, 126, 7186-7187.
16. (b)Yasuda, M.; Saito, T.; Ueba, M.; Baba, A. Angew. Chem., Int. Ed. 2004, 43, 1414-1416.
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18. We preliminary examined a catalytic hetero-Diels - Alder reaction. The use of the silicon-tethered borate 3aB THF gave higher yield (85%) than carbon-tethered borate 1B THF (77% ref 2). We are now investigating catalytic activities of them based on reaction rates.