Science of Synthesis

MacMillan, D. W. C.; Beeson, T. D., Science of Synthesis: Asymmetric Organocatalysis, (2012) 1, 303.

The formation of C—Cl bonds is also possible using SOMO catalysis, in which aldehydes are directly α-chlorinated with lithium chloride as the chlorine source in the presence of substoichiometric copper and sodium persulfate oxidants.[‌15‌] With the development of new imidazolidinone catalyst ‌30‌, reactions can be performed at ambient temperature without loss of enantioselectivity due to product enamine formation. While the products ‌31‌ obtained are analogous to those generated by two-electron enamine catalysis methods,[‌57‌,‌58‌] this method allows the selective chlorination of aldehydes in the presence of nucleophilic hetarenes such as indole (‌Scheme 32‌). Although the reaction proceeds well at ambient temperature, maximum enantioselectivities (91–96% ee) are achieved at 10 °C.

‌Meeeee 88‌ Meeeeeee Meeeeeeee ee eee Meeeeeeee α-Meeeeeeeeeee ee Meeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

M8	ee (%)	Meeee (%)	Mee
(MM8)8Me	88	88	[‌88‌]
(MM8)8MM=MM8	88	88	[‌88‌]
(MM8)8MMMM	88	88	[‌88‌]
Me	88	88	[‌88‌]
(M)-(MM8)8MM=MMMe	88	88	[‌88‌]
(MM8)8MM8Me	88	88	[‌88‌]
	88	88	[‌88‌]
	88	88	[‌88‌]

Mee α-eeeeee eeeeeeee eee eeee eeeeeeee ee ee e eeeeeeeeee eeeeeeee eeee eeeee eeee eeeeee eeeeeeeeeeeee eeeeee eeeeeeee eee ee eeeeeeee ee e eee-eee eeeeeee. Me eeee eeeeeeeeee eee eeeeeeeeee eeeeee eeeeeeee eeeeeeee eee eeeeeeeeee eeee eee eeeeeeeee α-eeeeeeeeeeee eeeeeeee eee eeeeeee eeeeee eeeeeeeeeeeeeee eeeeeeeee eeeeeeee eeeeeeee ‌88‌ eeee e eeee eeeeeeeee eee eeeeeeeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeee Meeeeeeee ee eee Meeeeeeeee ee Meeeeeee Meeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

M8	ee (%)	Meeee (%)	Mee
(MM8)8Me	88	88	[‌88‌]
(MM8)8MM=MM8	88	88	[‌88‌]
Me	88	88	[‌88‌]
(MM8)8MMe	88	88	[‌88‌]
(MM8)8M≡MMe	88	88	[‌88‌]
(M)-(MM8)8MM=MMMe	88	88	[‌88‌]
	88	88	[‌88‌]
	88	88	[‌88‌]

Meeeeeeeeeee Meeeeeeee

α-Meeeee Meeeeeeee ‌88‌; Meeeeee Meeeeeeee eee α-Meeeeeeeeeee ee Meeeeeeee:[‌88‌]

Me e 88-eM eeee-eeeeee eeeee (ee 88 °M) eeeeeeee eeee e eeeeeeee eeeeeee eee eee eeeeeee eeee (8M,8M)-8-eeee-eeeee-8,8-eeeeeeeeeeeeeeeeeeee-8-eee MMM eeee (‌88‌•MMM; 88 ee, 8.888 eeee, 8.8 eeeee), MeMe (88 ee, 8.888 eeee, 8.8 eeeee), Me(M8MMM8)8•M8M (88 ee, 8.888 eeee, 8.8 eeeee), eee Me8M8M8 (888 ee, 8.888 eeee, 8 eeeee) eee eeeee MeMM (8.8 eM) eee M8M (88 µM, 8.888 eeee, 8.8 eeeee). Mee eeeeee eee eeeeeee ee 88 °M eee 8 eee, eeeeee eee eeeeeeee eeeeeeeee (8.888 eeee) eee eeeee eee eee eeeeeee eee eeeeeee eeeeeeeeee eee 8 e ee 88 °M. Mee eeeeeee eee eeee eeeeee ee 8 °M eeeeee MeMM8 (888 ee, 8.888 eeee, 8 eeeee) eee eeeee. Meeee e eeeeeee 88 eee, eee eeeeee eee eeeeee ee ee eee 8 eee eee eeee eeeeeee eeee MeMMe (88 eM), eee eee. MM8Me (88 eM) eee eeeee. Mee eeeeeeeee eeeeeee eee eeee eeeeeee eeeeeeeeee eeeee eee eeeeeee eeeee eeeeee eeee eeee. Mee eeee eee eeeeeeeee eeee MeMMe (8 × 88 eM), eeeeee eeee eeeee (8 × 888 eM), eeeee (MeMM8), eeeeeeee, eee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eee eeeeeeeee eee ee eeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeee/MeMMe) eeeeeeee eee eeeee eeeeeeeee. Mee eeeeeeeeeeeeeeeeee eee eeeeeeeeee eeeeeeee ee MMMM ee ee eeeeeeeeeeeee eeeee eeeeeeeeeeeeee (MMM) eeeee eeeeeeeee ee eee eeeeeee eeee 8-eeeeeeeee eeeeeeee.

Meeeeeee ‌88‌; Meeeeee Meeeeeeee eee Me Meee Meeeeeeeee ee Meeeeeee Meeeeeee eeee α-Meeeee Meeeeeeee:[‌88‌]

Me e 88-eM eeee-eeeeee eeeee (ee 88 °M), eeeeeeee eeee e eeeeeeee eeeeeee eee eee eeeeeee eeee (8M,8M)-8-eeee-eeeee-8,8-eeeeeeeeeeeeeeeeeeee-8-eee MMM eeee (‌88‌•MMM; 88 ee, 8.88 eeee, 8.8 eeeee), MeMe (88 ee, 8.88 eeee, 8.8 eeeee), Me(M8MMM8)8•M8M (888 ee, 8.88 eeee, 8.8 eeeee), eee Me8M8M8 (888 ee, 8.88 eeee, 8 eeeee) eee eeeee MeMM (8.8 eM) eee M8M (88 µM, 8.88 eeee, 8.8 eeeee). Mee eeeeeeeee eeeeeee eee eeeeeee ee 88 °M eee 8 eee, eeeeee eee eeeeeeee eeeeeeeee (8.88 eeee) eee eeeee, eee eee eeeeeee eee eeeeeee eeeeeeeeee ee 88 °M eee 8 e. Mee eeeeeee eee eeee eeeeee ee 8 °M eeeeee MeMM8 (88 ee, 8.88 eeee, 8.8 eeeee) eee eeeee. Meeee e eeeeeee 88 eee, eee eeeeee eee eeeeee ee ee eee 8 eee eeeeee e eeeeeee eeeeeeee eeee ee ee MMM [8 eM ee e eeee ee MMM (88.8 e) eeeeeee ee eeeeeeeee M8M (88 eM)] ee MeMM (88 eM), eee eeeee eee eee eeeeeeeee eeeeeee eee eeeeeee eeeeeeeeee eee 88 eee. Me eeee eeeee, eeeeeeeee M8M (88 eM) eee eeeee ee eee eeeeee eeeeee ee eee eeeeeeeee eeee Me8M (8 × 88 eM), eeeeee eeee eeeee (8 × 88 eM), eeeee (MeMM8), eeeeeeee, eee eeeeeeeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee (888–888 Meee). Meeeeeeeeeee ee eee eeeeeeeee eee ee eeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeee/Me8M) eeeeeeee eee eeeee eeeeeeeee. Mee eeeeeeeeeeeeeeeeee eee eeeeeeeeee ee MMMM eeeeeeee ee eeeee eeeeeee eeeeeee eeee eeeeeeeeeee-8-eeeee.

References