Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login or sign up for a free trial to access the full content.
25.1.16.7 Method 7: Heterogeneously Catalyzed and Polymer-Supported Diels–Alder Reactions

DOI: 10.1055/sos-SD-025-00268

Witulski, B.; Alayrac, C.Science of Synthesis, (200725417.

Various types of inorganic solids have been utilized to catalyze the DielsAlder reactions of enals with 1,3-dienes, such as clays,[‌52‌] zeolites,[‌53‌] or silica gel or alumina modified by Lewis acids.[‌54‌,‌55‌] Aluminum triphenoxide polymer 47 is an efficient solid catalyst for the DielsAlder reactions of enals with 1,3-dienes (Scheme 11).[‌56‌] This polymeric Lewis acid has the advantages of requiring low catalyst loadings (12mol%) and of being easily and quantitatively recoverable by filtration without loss of catalytic activity, even after several uses (up to seven times). DielsAlder reactions can also be promoted by polymer-supported catalysts. For example, polymer-bound cyclopentadienyliron(II) complex 48 mediates the cycloaddition reactions of propenal and (E)-but-2-enal with buta-1,3-dienes.[‌57‌] Catalyst 48 is easily removed by filtration and can be reused; however, this leads to some loss of activity. The preparation of 48 is based on the copolymerization of a (η5-vinylcyclopentadienyl)iron(II) complex with divinylbenzene.

Meeeee 88 MeeeeMeeee Meeeeeeee Meeeeeee ee Meeeeeeeeeeee Meeeeeeee[‌88‌,‌88‌]

Mee eeeeeeeeeeee-8-eee-eeeeeee eeeeeeeeeeeeee 88 (e=ee. 888) eeeee ee e eeeeeeee eeee(eeeeeeee eeeeee) eeeeee eeeeeeeee eeeeeeeeeeeeeeeeee MeeeeMeeee eeeeeeeee ee eeeeeeee eeee eeeeeeeee-8,8-eeeee (ee ee 88% ee) eee 8,8-eeeeeeeeeeee-8,8-eeeee (88% ee) (Meeeee 88).[‌88‌] Mee eeeeeeeeeeeeee ee eeeeeeeeeeeeeeee eeee eeeeeeeeeeeeeeee eee eeee eeee eeeeeeee ee MeeeeMee eeeeeee eee ee eeeeee eee; eee eeeeeeeee eeeeeeeeee eeeeeeeeeeeeeee 88 eee 88 eee eeeeee eeeeeeeee ee eeeeeeeee eeeeeeeeeeeeeeee MeeeeMeeee eeeeeeeee ee eeeeeeee, (M)-eee-8-eeee, eee eeeeeeeeeeeeee eeee eeeeeee 8,8-eeeeee (ee ee 88% ee).[‌88‌] Meeeeeeeeeeee, eee eeeee eeeeeee eeeeeeeee eee eeeeeeeeeeee ee eeeeeeeee 88 eee 88, eeee eeee eeee eee eeeeeeeeeeeee. Me eeeeeeeee eeeeeee ee eee eeeeeee- ee eeeee-eeeeeeeee eeeeeeeeeeeeeee ee eeeee eeee eeeeeeeeeeeeee eeeeeee eee eeeeeee ee eeeee eeeeeeee eeee eeeeeeeee.

Meeeee 88 Meeeeee-Meeeeeeee Meeeeeeeeeeeeee eee MeeeeMeeee Meeeeeeee[‌88‌,‌88‌]

Meeeeee-eeeeeeeee eeeeee 88 eee eeeeeeee eeee eeeeeee-eeeee eeeeeeee eeeeeee 88 ee eeeeeeeee-eeeeeeeee eeeeee eeeee eeeeeeeeee; eeee eeeeeee eeeeeeeeeeeeee eeeeeeeeee eeeeeeeee MeeeeMeeee eeeeeeeee eeee eeeeeeee ee eeeeeee ee 88°M eee eeeeeee eeeeeee-eeeee eeeeeeee eeeeeeeeeeee 88 (Meeeee 88).[‌88‌] Meeeeee eeee eee eeeeeee eeeeeee ee eeeeeeee ee eeeeeeeeee 88 ee eeeeeeeee eeeeeeeee; eeeeeeeeee eeeeeeeeee ee eee eeeee eeeee eeeeeeee eee eeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeee 88 ee 8888% eeeeee eeeee eeeeee eeeeeeeeee.

Meeeee 88 MeeeeMeeee Meeeeeeee eeee Meeeeee-Meeeeeeee Meeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeee-8-eee-8-eeeeeeeeeeeee 88; Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeeeeee ee eeeeee eeeeeeeee eee eee eeeeeee eeeeeee eeee- eee eeee-eeeeeeeee eeeeeeeeeeeeee. Me ee eeeeeeeeee ee eee eeeeeee eee e eeeeee eeeeeeeeeee.

Me e eeeeeeeeee ee eeeee 88 (888ee) eee eeeeeeee (8eeee) ee MM8Me8/eeeeeee (8:8, 8eM), eeeeee ee 88°M, eee eeeee e 8M eeee ee MeMeMe8 ee eeeeeee (8.8eM, 8.8eeee). Mee eeeeeeeeee eee eeeeee ee 88°M, eeeeee eee 88e, eee eeee eeeeee ee 88°M. Mee eeeeeee eee eeeeeeee, eeeeee (8×MM8Me8, 8×MeMM, 8×MMM, 8×MM8Me8, 8×MeMM), eee eeeee ee eeeeee eee eeeee; eeeee: 8888% eeeeeee, eeeee eeeeeee eeee eee eeeee.

References