Table 5.

Screening of the reaction conditions for the cyclopropanation of methylacrylate with sodium benzyl tosylhydrazone salt catalysed by [Co(MeTAA)].^[a]

	Solvent	PTC[c]	Additive[d]	T [°C]	t [h]	Yield [%]	trans/cis
1	CH3CN	–	–	45	18	80	74:26
2	THF	–	–	45	18	67	76:24
3	PhMe	–	–	45	18	47	75:25
4	PhCl	–	–	45	18	52	76:24
5	Dioxane	–	–	45	18	13	–
6	1,2‐Dichloro ethane	–	–	45	18	38	74:26
7	DMF	–	–	45	18	64	75:25
8[b]	MeOH	–	–	45	18	–	–
9	THF	Aliquat® 336	–	45	18	>99	76:24
10	THF	Aliquat® 336	–	45	4	>99	76:24
11	THF	Aliquat® 336	–	45	2	>99	76:24
12	PhMe	Aliquat® 336	–	45	18	>99	76:24
13	PhCl	Aliquat® 336	–	45	18	94	75:25
14	THF	Aliquat® 336	–	20	18	85c	76:24
15	CH2Cl2	Aliquat® 336	–	20	18	16c	–
16	CH2Cl2	–	–	20	18	–	–
17	THF	–	1‐methyl‐ imidazole	45	18	96	75:25
18	THF	–	DMAP	45	18	86	74:26
19	THF	–	pyridine	45	18	>99	76:24
20	THF	–	2,4,6‐trimethyl pyridine	45	18	>99	76:24

[a] Reactions were performed under N₂ with 1.0 equiv. of sodium benzyl tosylhydrazone, 3.0 equiv. of methylacrylate and 3 mol % [Co(MeTAA)]. Concentration: 0.675 mmol sodium benzyl tosylhydrazone/5 mL solvent; [b] methyl 3‐methoxypropanoate is obtained as the sole product; [c] 0.15 equiv. Aliquat®336; [d] 0.5 equiv. additive. [f] Aliquat ® 336 is a quaternary ammonium salt that contains a mixture of C₈ (octyl) and C₁₀ (decyl) chains (predominantly C₈) and a chloride counter ion.