Table 2. Pronucleophile and ligand screening in the isocyanoacetate aldol reaction between 8 and 7  ^a .

Entry	R	7	Ligand	Time (min)	Yield b (%)	d.r. c (trans : cis)	e.e. d (%)
1	(CH3)3C	7a	L-1	30	70	91 : 9	78
2	CH3	7b	L-1	100	80	88 : 12	82
3	PhCH2	7c	L-1	180	61	90 : 10	87
4	PhCH2	7c	L-2	80	64	90 : 10	87
5	4-(OCH3) C6H4CH2	7d	L-2	60	63	89 : 11	86
6	3,5-(CF3)2 C6H3CH2	7e	L-2	60	56	90 : 10	84
7	Ph2CH	7f	L-1	100	81	93 : 7	87
8	Ph2CH	7f	L-2	45	78	91 : 9	89
9	Ph2CH	7f	L-3	200	82	93 : 7	88 e
10	Ph2CH	7f	L-4	60	68	92 : 8	93 e

^aReaction performed on 0.25 mmol of 7 (0.01 M in AcOEt) using 1.1 eq. of 8. Configuration of 6 assigned by analogy with previous work.⁹

^bIsolated yield of trans diastereomer after FCC.

^cd.r. determined by ¹H NMR analysis of the crude reaction mixture.

^de.e. of trans diastereomer determined by HPLC on chiral stationary phase.

^eOpposite enantiomer obtained.