Asymmetric 1,4-hydrosilylations of α,β-unsaturated esters

Journal of the American Chemical Society

Volumn 126, Issue 27, 2004, Pages 8352-8353

  Lipshutz, Bruce H ^a   Servesko, Jeff M ^a   Taft, Benjamin R ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CARBONYL DERIVATIVE; COPPER COMPLEX; ESTER; LACTONE; LIGAND; METAL COMPLEX; REAGENT;

ARTICLE; CATALYSIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; DIASTEREOISOMER; ENANTIOMER; PROTON NUCLEAR MAGNETIC RESONANCE; SILYLATION; STEREOCHEMISTRY;

EID: 3142779334     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja049135l     Document Type: Article

References (14)

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2. (b) Hughes, G.; Kimura, M.; Buchwald, S. L. J. Am. Chem. Soc. 2003, 125, 11253.
3. Krause, N.; Hoffmann-Roder, A. Synthesis 2001, 171.
4. For selected examples, see ref 1b.
5. Chen, J.-X.; Daeuble, J. F.; Brestensky, D. M.; Stryker, J. M. Tetrahedron 2000, 56, 2153.
6. Saito, T.; Yokozawa, T.; Ishizaki, T.; Moroi, T.; Sayo, N.; Miura, T.; Kumobayashi, H. Adv. Synth. Catal. 2001, 343, 264.
7. (a) Lipshutz, B. H.; Noson, K.; Chrisman, W.; Lower, A. J. Am. Chem. Soc. 2003, 125, 8779.
8. (b) Lipshutz, B. H.; Shimizu, H. Angew. Chem., Int. Ed. 2004, published online February 16, http://dx/doi.org/10.1002/ anie.200353294.
9. (c) Lipshutz, B. H.; Servesko, J. M.; Peterson, T. B.; Papa, P. P.; Lover, A. L. Org. Lett. 2004, 6, 1273.
10. (a) Product R-4 (R′ = Me) was saponified to the known, commercially available acid (Fluka).
11. (b) Product S-6, R = Et, is known; Norsikian, S.; Marek, I.; Klein, S.; Poisson, J. F.; Normant, J. F. Chem. Eur. J. 1999, 5, 2055.
12. R,S-2, S,R-2, and R,R-2 are all available from Solvias, Inc.; cf. Blaser, H.-U.; Brieden, W.; Pugin, B.; Spindler, F.; Studer, M.; Togni, A. Top. Catal. 2002, 19, 3.
13. 4/dioxane). The resulting cis-disubstitued butyrolactone, indicative of the R-stereochemistry at the β-site, was readily confirmed by NMR (cf. Supporting Information).
14. It is likely that CuH (20 mol % present) and t-BuOH (1.1 equiv) undergo facile H/D-exhange at room temperature, which accounts for the (16%) deuterium incorporation at the β-site. If copper hydride remains deuterated given excess t-BuOD and thus accounts for 20 mol % of the deuterium present, the maximum level of D incorporation is 90% (1.1 equiv t-BuOD = 110% D available - 20% in the form of CuD). Thus, 77% (29% + 32% + 16% D incorporation, based on NMR integrations) of this 90%, or 85.5% deuteration has occurred.