By Yamamoto
Read Online or Download Lewis Acid Reagents - A Practical Approach PDF
Best nonfiction_7 books
Fluorescence in Bio-inspired Nanotechnology: First as Probe, Then as Function
In his thesis Fluorescence in Bio-inspired Nanotechnology, Jonas Hannestad describes the evolving box of DNA nanotechnology in a lucid and simply obtainable approach. A valuable subject within the thesis is how organic constructions and mechanisms represent a foundation for the layout of novel applied sciences. Hannestad discusses how self-assembled, nanometer-scale DNA constructs could be functionalized utilizing fluorescent labeling.
Additional info for Lewis Acid Reagents - A Practical Approach
Sample text
1992,114,1089. 27. ; Yamamoto, H. Bull. Chem. Soc. Jpn 1988, 61, 2975. 28. ; Yamamoto, H. J. Am. Chem. Soc. 1988,110, 310. 29. ; Yamamoto, H. /. Am. Chem. Soc. 1989, 111, 789. 30. ; Yamamoto, H. , 1988, 29, 3967. 31. ; Nozaki, H. Bull. Chem. Soc, Jpn 1986, 57, 446. 32. ; Yamamoto, H. J. Am. Chem. Soc. 1995,117, 6153. 33. ; Yamamoto, H. /. Am. Chem. Soc. 1990, 112,316. 34. ; Yamamoto, H. J. Am. Chem. Soc. 1990,112,7791. 35. ; Yamamoto, H. Tetrahedron-Asymmetry 1991, 2, 647. 36. ; Yamamoto, H. Synlett 1991, 793.
Seal the reaction flask and allow to warm to the reaction temperature. 4. Quench the reaction with 10% NaHCOa (aq) and isolate the products (95% yield) by flash chromatography. ^ * Chiral GC analyses are performed with J&W Cyclodex-B p-cyclodextrin column. Mukaiyama et al. ^'"''^ For example, methacrolein and cyclopentadiene afford the exo adduct (exo:endo = >99:1) in 97% ee (20 mol% of catalyst). 18). ^^ In the hypothetical transition-state model 17, one of the A'-CH2Ar substituents serves to block attack on the lower face of the s-transco-ordinated dienophile whereas the other screens another region in space and limits the rotational position of dienophile and A^-CH2Ar moieties.
This study demonstrates the potential for broad application of the in situ generated chiral catalyst via diastereoselective complexation in asymmetric synthesis. 19). 19 20 88% ee ( 90% ) 88% ee ( 8 8 % ) 2: Synthetic use of bulky aluminium reagents as Lewis acid receptors 5. Claisen rearrangement Aliphatic Claisen rearrangements normally require high temperatures. However, in the presence of Lewis acidic organoaluminium reagents, the rearrangements have been accomplished under very mild conditions.