Table 1.

Optimisation of amine coupling for retention of ee and yield.

Entry	Solvent	Additive	Yield [%][a]			[% es][c]
			(R)‐2 a	(R)‐3 a	total[b]
1	THF	–	30	52	82	8
2	THF	TMS‐Cl	75	1	76	n.d.
3	THF	H2O	6	77	83	26
4	THF	KBr	33	44	77	13
5	THF	LiCl	11	31	42	>99
6	THF	LiBr	19	56	75	>99
7	EtOH	–	–	33	33	45
8	iPrOH	–	6	66	72	29
9	MeCN	–	9	73	82	28
10	MeCN	LiBr	–	96	96	>99
11	MeCN	LiI	–	87	87	>99

Optimisation of reaction conditions for yield and ee of (R)‐3 a. Reactions were performed using 0.1 mmol (R)‐2 a. [a] Yields determined by ¹H NMR spectroscopy by using 1,3,5‐trimethoxybenzene as internal standard. [b] Sum of preceding two columns. [c] es=enantiospecificity, given by % ee _(R)‐3 a/% ee _(R)‐2 a. For details on Procedure C, see the Supporting Information.