Table 2.

(S,S)-PBAM·HOTf–Catalyzed Enantioselective aza-Henry Addition to Aliphatic N-Boc Imine Intermediates: Substrate Scope

entrya	R	ent-4	yieldb (%)	eec (%)
1	PhCH2CH2	a	70	93
2	Et	b	90	81
3	nPr	c	87	90
4	nBu	d	94	88
5	C10H21	e	88	90
6	(CH3)3CCH2	f	88	90
7	iBu	g	83	92
8	(C6H11)CH2	h	82	85
9	PhCH2	i	39	89
10	iPr	j	59	79
11	cyclo-C3H5	k	61	90
12	Cy	l	61	92
13	H2C=CHCH2CH2	m	77	84
14	cis-EtCH=CH(CH2)2	n	80	89
15	HC≡CCH2CH2	o	63	86
16	HC≡CCH2CH2CH2	p	73	91
17	CF3CH2	q	57	85
18	p(MeO)PhCH2CH2	r	68	90
19	EtOCH2CH2	s	68	76

^aReaction filtered through Celite to remove Cs₂CO₃ prior to second step. The reaction time for the second step was 24 h.

^bIsolated yields.

^cAdducts isolated as a mixture of diastereomers (1:1), ee’s re-ported as an average of diastereomer ee’s (Δ% ee≤3).