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2.1.1.4.1.1 Michael Reactions with β-Keto Esters

DOI: 10.1055/sos-SD-205-00001

Nagasawa, K.; Sohtome, Y.Science of Synthesis: Asymmetric Organocatalysis, (2012222.

In 2009, Feng and co-workers described efforts targeted at the development of the structurally constrained guanidineamide organocatalyst 59 and its application to the catalytic Michael reaction of β-keto ester 57 with nitroalkenes 58. This catalyst effectively promotes these Michael reactions to give products 60, in a process that introduces two contiguous stereocenters including a quaternary carbon atom. As the observations summarized in Scheme 21 show, the guanidineamide catalyst 59 displays remarkable activity for a wide range of nitroalkenes, giving good to excellent yields (5499%) and high stereoselectivities [dr (syn/anti) 89:11 to 99:1; 8397% ee (syn)].

Meeeee 88 Meeeeeeee Meeeeeeeee Meeeeee Meeeeeeee ee Meeeeeeeeeee eeee e β-Meee Meeee Meeee e MeeeeeeeeMeeee Meeeeeeeeeeeee[‌88‌]

Meeeeeeeeee 88

M8 Meeeeee 88 (eee%) Meee (e) Meeee (%) ee (eee/eeee) ee (%) Mee
Me MeMMe 8 88 88 88:8 88 [‌88‌]
8-Mee MeMMe 8 88 88 88:88 88 [‌88‌]
8-Mee MeMMe 8 88 88 88:8 88 [‌88‌]
8-Mee MeMMe 8 88 88 88:8 88 [‌88‌]
8-MeMM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8-MeMM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8,8-(MeM)8M8M8 MeMMe/MMM (8:8) 8 88 88 88:8 88 [‌88‌]
MeMMe/MMM (8:8) 8 88 88 88:8 88 [‌88‌]
8-MeM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8-MeM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8-MeM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8,8-Me8M8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8,8-Me8M8M8 MeMMe 8 88 88 88:88 88 [‌88‌]
8-MM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8-MeM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8-M8MM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
8-eeeeeeee MeMMe 8 88 88 88:8 88 [‌88‌]
8-eeeeeeee MeMMe 8 88 88 88:88 88 [‌88‌]
8-MeM8M8 MeMMe 8 88 88 88:8 88 [‌88‌]
MeMMe 8 88 88 88:8 88 [‌88‌]
(M)-MM=MMMe MeMMe 8 88 88 88:8 88 [‌88‌]
MeMMe 8 88 88 88:8 88 [‌88‌]
8-eeeee MeMMe 8 88 88 88:8 88 [‌88‌]
8-eeeeeee MeMMe 8 88 88 88:8 88 [‌88‌]
Me MeMMe 8 88 88 88:8 88 [‌88‌]

M-eee eee MMM eeeeeeee ee 88 eeeeeee eeeee eee eeeeeeeee ee ee eeeeeeeeeeeeee eeeeeeee-eeeeeee eeeeeeeeeee eeeeeee e eeeeeeee eeee ee eee eeeeeeeee eeeeee eee eee eeeee eeeeee. Me eeeeeeee, eee eeeeeeeeeee eeee eee M-eeeeee eeeeeeeeee ee 88 eeeeeeee e eeeeeeeeee eeeeeeeee eeeeeeeee eeeeeeee eeeeeeee eeee eee eeeee eeeeee ee 88 eeee ee e Meøeeeee eeee ee eee eeeeeeeee eeeeeee. Meeee ee eee eeeeeee ee eeeee eeeeeeeeeee eeeeeeeeeee eeeeeee, eee eeeeeee eeeeeeee e eeeeeeeeee-eeeee eeeee eee eeeee eeeeeeeee eeee eeeeeeee eee eeeeeeee eee-eeeeeeeeeeeee. Me eeee eeeee, eeeeeeeeeeee eeeeeeee eeeee eeee eeee eee Meeeeee eeeee, eeeee eee MM eeeeee ee eee eeeee eeeeeeeeeee ee eee Meeeeee eeeeeeee (Meeeee 88).[‌88‌]

Meeeee 88 Meeeeeee Meeeeeeeee-Meeee Meeee eee Meeeeee Meeeeeeee ee Meeeeeeeeeee eeee e β-Meee Meeee Meeeeeeee ee e MeeeeeeeeMeeee Meeeeeeeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

eeee-Meeee 8-(8-Meeeeeeeee)-8-eeeeeeeeeeeeeeeeeeeeeeeeeee 88; Meeeeee Meeeeeeee:[‌88‌]

β-Meee eeeee 88 (88.8ee, 8.88eeee) eee eeeee ee e eeeeeee eeee ee eeeeeeeeeee 88 (8.8eeee, 8.88 eeeee) eee eeeeeeeee 88 (8.8ee, 8.888eeee, 8eee%) ee MeMMe (eeeeeeeeee eeeeeee eeeee; 8.88eM) ee 88°M. Meeee eeeeeeee eee 88e, eee eeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeee e eeeeeee, eeeee eee eeeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee).

References


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