ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Catalytic control of regio-, diastereo-, and enantioselectivity in the 1,3-dipolar cycloaddition of 3-acryl-oyloxazolidin-2-one (4) with different nitrones 2 by the application of a [TiX2(TADDOLato)] complex as the catalyst was developed (TADDOL = α,α,α′,α′-tetraaryl-1,3-dioxolane-4,5-dimethanol). In the absence of a catalyst, the 1,3-dipolar cycloaddition of 4 with 2 proceeded to give a mixture of regioisomers, whereas, in the presence of a catalyst, the regioselectivity of the reaction could be controlled. Three asymmetric [TiX2(TADDOLato)] catalysts were tested, and it was found that use of the [Ti(OTs)2(TADDOLato)] complex gave complete regioselectivity, high ‘endo’-selectivities (〉 90% d.e.), and enantioselectivities corresponding to 48-70% e.e.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19970800704
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