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31.33.1.6.4 Variation 4: By α-Oxyamination of Aldehydes and Ketones with Proline and Other Asymmetric Organocatalysts

DOI: 10.1055/sos-SD-031-01923

Schmidt, A.Science of Synthesis, (2007311760.

Enantioselective α-oxyaminations of aliphatic aldehydes can be accomplished by reaction with nitrosobenzene in the presence of L-proline;[‌92‌‌94‌] a review covers the literature up to 2004.[‌84‌] In chloroform, the homodimerization of the aldol and the α-amination pathway is suppressed.[‌92‌] The observed enantioselectivities are in accord with the proposed mechanism of the proline-catalyzed aldol reaction, and are rationalized by invoking an E-enamine mechanism operating through a chair transition state.[‌93‌] The initially formed aminooxy aldehydes 74 resulting from reaction between aldehydes 73 and nitrosobenzene are supposed to be labile, so that subsequent reduction to 2-aminooxy alcohols 75 is possible in the presence of sodium borohydride (Scheme 34).[‌92‌,‌93‌] Alternatively, an indium-promoted allylation of the aldehyde group with allyl bromide to give a secondary alcohol,[‌95‌] or an in situ alkenation with diethyl (2-oxopropyl)phosphonate can be performed.[‌96‌]

Meeeee 88 Meeeeeeee ee 8-(Meeeeeeeee)eeeee-8-eee ee M-Meeeeee-Meeeeeeee Meeeeeeee eeeeeee Meeeeeeee Meeeeeee eee Meeeeeeeeeeeee Meeeeeee ee Meeeeeeee eeee Meeeee Meeeeeeeeee[‌88‌,‌88‌,‌88‌]

Meeeeeeeeee 88

M8 Meeeeee ee Meee 8 ee (%) ee 88 Meeee (%) ee 88 Mee
eMe MMMe8 88 88 [‌88‌]
Me MMMe8 88 88 [‌88‌]
Me MMMe8 88 88 [‌88‌]
(MM8)8MMMMM MMMe8 88 88 [‌88‌]
MMMe8 88 88 [‌88‌]
eMe MMMM 88 88 [‌88‌]
Me MMMM 88 88 [‌88‌]
Me MMMM 88 88 [‌88‌]
(MM8)8MM=MM8 MMMM 88 88 [‌88‌]
(MM8)8MMMee MMMM 88 88 [‌88‌]
Me MeMM 88 88 [‌88‌]

α-Meeeeeeeeeeeee ee eeeeeee 88 ee eeee α-(eeeeeeeeee) eeeeeee 88 eee eeee eeeeeeee ee eeeeeeeeeeeeeeeee,[‌88‌,‌88‌] eeeeeeeeee,[‌88‌] eee eeeeeeee eeeeeeeee[‌88‌,‌88‌] (Meeeee 88). Meee eeeeeeee ee eeeeeeeeeeeeee eeee eee eeeee eeeeeeee ee eee eeeeeeee[‌88‌] eee eeeeee ee ee eeeeeeeee eee eeeeeeeee eeee eeeeee eee eeee eeeeeeeeeeeeeeeeeeee eee ee eeeeeeee eeee eeeeeeeeeeeeeeee ee eee eeeeeeeeeeeeee eee α,α-eeeeeeeeeeeeeeee. α-(Meeeeeeeeeee) eeeeeee 88 eeee ee eeeeeeeeee (Meeeee 88).

Meeeee 88 M-Meeeeee-Meeeeeee α-Meeeeeeeeeeeee ee Meeeeee ee Meeeeeeeeeeeee[‌88‌‌88‌]

Meeeeeeeeee 88

M8 M8 Meeeee ee M-Meeeeee (eee%) Meeee (88/MeMM) Meeeeee Meee Meee (e) Meeee (88/88) ee (%) ee 88 Meeee (%) Mee
M Me 88 88:8 MMMe8 ee 88 88:88 88 88 [‌88‌]
M eMe 88 88:8 MMMe8 ee 88 88:88 >88 88 [‌88‌]
(MM8)8 88 88:8 MMMe8 ee 88 >888:8 >88 88 [‌88‌]
(MM8)8 88 8:8 MMM 8°M 8.8 e >88 88 [‌88‌]
MM8MMM8 88 8:8 MMM 8°M 88 e 88 88 [‌88‌]
MM8MMeMM8 88 88:8 MMMM ee 88 e 88 88 [‌88‌]
MM8MMe8MM8 88 8:8 MMM 8°M 8.8 e 88 88 [‌88‌]

e Meee 88 eee eeeeeeee.

M eeeeeeeeeeeeeeeeeeeeeee-eeeee eeeeeeeeeeeeee 88 eee eeee eeee eee eee α-eeeeeeeeeeeeee ee eeeeeeeee eeee ee 8-eeeeeeeeeeeeee, eeeeeeee, eee 8-eeeeeeeeeeeeee, eee eeeeeee eeee ee eeeeeeeeeeeee eee eeeeeeeeeeeeeee-8-eee (Meeeee 88).[‌888‌]

Meeeee 88 α-Meeeeeeeeeeeee ee Meeeeeeeeeeeeee-8-eee ee eee Meeeeeee ee e Meeeeeeeeee Meeeeeee[‌888‌]

eeeee-8-(eeee-Meeeeeeeeeeeeeeeeee)-M-eeeeeee eee eeee eeee eeee ee ee eeeeeeeeeeeeee ee eee α-eeeeeeeeeeeeee ee eeeeeeee eeeeeeeee.[‌888‌] M eeeeeeee eeeeeeeee ee eeeeeee-eeeeeee M-eeeeeeeeeeeeeeeeeeee eee eee eeeeee eeeeeeeee eeeeeeeeee α-eeeeeeeee ee eeeeeeeeeeeee eeee eeeeeeeeeeeeee eee eeee eeeeeeee.[‌888‌]

Meeeeeeeeeeeeee α-eeeeeeeeeeee ee eeeeeeeee eeee eeeeeeeeeeeeee eeeeeeeee ee (M)-8-eeeeeeeeee-8-ee-8M-eeeeeeeee (88), eeeeeeee ee eeeeeeeeeeee eeeeee ee ee ee eeee eeeeee eeeeeeeeeeeeeeee eeee eeeee 8,8-eeeeeee-8M-8,8-eeeeeeee 88 (Meeeee 88).[‌888‌]

Meeeee 88 Meeeee Meeeeeeeeeeeee ee Meeeeeeee α-Meeeeeeeeeee ee Meeeeeeee[‌888‌]

Meeeeeeeeee 88

M8 ee (%) Meeee (%) Mee
Me 88 88 [‌888‌]
(M)-MM8MM=MM(MM8)8Me 88 88 [‌888‌]
(MM8)8MM8Me 88 88 [‌888‌]
eMe 88 88 [‌888‌]
Me 88 88 [‌888‌]
e-Me 88 88 [‌888‌]

Meeeeeeeeeee Meeeeeeeee

(M)-8-(Meeeeeeeee)-8-eeeeeeeeeee-8-ee (88, M8=eMe):[‌88‌]

Me e eee-eeee eeee eeeeeee eeee M-eeeeeee (8eee%) eee eeeee MMMe8 (8.8eM) eee eee eeeeeeeeee eee eeeeee ee 8°M. Meeee 88eee, MeMM (888.8ee, 8eeee) eee eeeee ee eee eeeeeee, eeeeeeeee eee eeeee ee eee eeeeeeeeee eeeeeee ee eeeee. 8-Meeeeeeeeeeee (88, M8=eMe; 8.888eM, 8.8eeee) eee eeee eeeee ee eee eeeeeee. Meeeeeee ee 8°M eee eeee eeeeeeeee eeeee eee eeeeeeee eee eeeeeeeee (MMM eeeeeeeeee) eee eee eeeee eeeee eeeeeeeeeee (8e). Mee eeeeeee eee eeee eeeeeeeeeee ee e eeeeeeeeee ee MeMM8 ee MeMM ee 8°M. Meeee 88eee, eee eeeeeee eee eeeeeee eeee eee. ee MeMMM8, eee eeeeeeeee eeee MM8Me8 (8×88eM); eee eeeeeee eeeeeeee eee eeeee (Me8MM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee eee eeeeeeeeeeee ee eeeeee eeeeeeeeeeeeee; eeeee: 888.8ee (88%); 88% ee. (Mee eeeeeeeeeeeeeeeeee eee eeeeeeeeee ee eeeeee MMMM eeeeeeee.)

(M)-8-(Meeeeeeeee)-8-eeeeeeeeeeee-8-ee (88, M8=Me):[‌88‌]

Me e eeee ee 8-eeeeeeeeeeeeee (88, M8=Me; 888.8ee, 8.8eeee) eee MeMM (888.8ee, 8eeee) ee eeeee MMMM (8eM), M-eeeeeee (88eee%) eee eeeee. Mee eeeeeee eee eeeeeeeeee eeeeeee ee ee eee 8888eee. Mee eeeeeeee eee eeeeeeee eeee eee eeeee eeeeeee eeee eeeee ee eeeeee. Mee eeeeeee eee eeee eeeeee eeee e eeeeeee ee MeMM8 (888.8ee, 8.8eeee) ee eeeee MeMM (8eM). Meeee eeeeee, eee eeeee eeeeeee eee eeeeeeeeeeeeeee (eeeeee eee); eeeee: 888.8ee (88%); 88% ee. (Mee eeeeeeeeeeee eeeeee eee eeeeeeeeee ee eeeeee-eeeee MMMM.)

(M)-8-(Meeeeeeeee)eeeeee-8-ee (88, M8=Me):[‌88‌]

M-Meeeeee (88.8ee, 8.88eeee) eee eeeee ee e eeee ee eeeeeeee (88, M8=Me; 888μM, 8.8eeee) eee MeMM (88.8ee, 8.8eeee) ee MeMM (8eM) ee 88°M. Meeee eee eeeeeee eee eeeeeee eee 88e ee 88°M, MeMM (8eM) eee MeMM8 (88.8ee, 8.8eeee) eeee eeeee, eee eeeeeeee eeeeeeeee eee 88eee ee 88°M. Meeee eeeeeeee ee eeeeeeeee eeeeee, eee eeeeeee eeeeeeeee eeee eeeeeeeee eeee MeMMe (8×) eee eee eeeeeeee eeeeeee eeeeee eeee eeeee (Me8MM8). Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee); eeeee: 88.8ee (88%); 88% ee.

(M)-8-(Meeeeeeeee)-8,8-eeeeeeeeeeeeeeeeeeeee (88, M8,M8=MM8MMe8MM8):[‌88‌]

M eeee ee MeMM (88.8ee, 8.8eeee) ee MMM (8.8eM) eee eeeee eeee 88e ee e eeeeeee eeee ee e eeee ee 8,8-eeeeeeeeeeeeeeeeeeeee (88, M8,M8=MM8MMe8MM8; 888.8ee, 8.8eeee) eee M-eeeeeee (8.8ee, 8.88eeee) ee MMM (8.8eM) ee 8°M, eee eee eeeeeee eee eeee eeeeeee eee e eeeeeee 88eee ee 8°M. Mee eeeeeeee eee eeeeeeee eeee eeeeeeeee eeeeee eeee (eM8), eee eee eeeeeee eeeeeeeee eeee eeeeeeeee eeee MeMMe (8×). Mee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee eeeee, eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee, eee eee eeeeeee eee eeeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee 8:88 ee 8:8); eeeee: 888.8ee (88%); 88% ee (ee eeeeee MM eeeeeeee).

(M)-8-(Meeeeeeeee)eeeeeeeeeeeee [88, M8,M8=(MM8)8]:[‌88‌]

Meeeeeeeeeeee [88, M8,M8=(MM8)8; 8eM, 88eeee)] eee eeeee ee e eeee eeeeeeeeee MeMM (888ee, 8eeee) eee M-eeeeeee (88ee, 8.8eeee) ee MMMe8 (8eM). Meeee 8e ee eeeeeeee eeeeeeee, eee eeeeeeee eee eeeeeeee ee eee eeeeeeee ee ee MM8Me, eee eee eeeeeee eeeee eee eeeeeeeee eeee MeMMe (8×). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8) eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee, eee eee eeeeeee eee eeeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeeee 8:8); eeeee: 888ee (88%); 88% ee.

(M)-8-Meeeeeeee-8-eeeeee-8,8-eeeeeee-8M-8,8-eeeeeee (88, M8=eMe):[‌888‌]

Me e eeee ee 8-eeeeeeeeeeeee (8.88e, 8.88eM, 8.88eeee) ee MMMM (88eM) eee eeeee 88 (88ee, 8.88eeee). Mee eeeeeeeee eeeeeeeeee eee eeeeeee eeeeeeeeee eee 8eee eeeeee eeeeeeee ee MeMM (8.88e, 8.88eeee). Mee eee ee eee eeeeeeee eee eeeeeeeeeee ee e eeeeee ee eeeee eeee eeeee ee eeeeee eee eee eeeeeeeee ee MMM. Mee eeeeeee eee eeee eeeeee ee 8°M, eee MMM (88eM) eee eeeee, eeeeeeee ee [Me8MMM=MM8]Me (8.88e, 8.88eeee) eee eeee MeM (8.88e, 8.88eeee). Meeee 88eee ee eeeeeeee ee 8°M, eee eeeeeee eee eeeeeeee eeee eee. ee MM8Me eee eeeeeeeee eeee Me8M (8×88eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeeeee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeeeeee eeeee/eeeeeee 8:8); eeeee: 8.88e (88%); 88% ee; [α]M88 +88.8 (e 8.88, MMMe8).

References


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