Table 2. Enantioselective C–H Insertion with Diazo Esters 11^a.

entry	R	catalyst	solvent	yield %b	cis:trans	ee, cis (%)	ee, trans (%)
1	Me	Rh2(S-PTTL)4	DMB	71	1.4:1	45	80
2	Me	Rh2(S-PTTL)4	CHCl3	63	1.6:1	49	67
3	Me	Rh2(S-PTTL)4	c-C6H12	69	1.6:1	41	77
4	t-Bu	Rh2(S-PTTL)4	DMB	55	3.0:1	<5	66
5	t-Bu	Rh2(S-PTTL)4	CHCl3	28	3.0:1	<5	57
6	t-Bu	Rh2(S-PTTL)4	c-C6H12	70	3.5:1	23	59
7	Me	Rh2(S-PTA)4	c-C6H12	79	1.0:1	18	57
8	Me	Rh2(R-PTV)4	c-C6H12	76	1:1.1	∼42	∼78
9	Me	Rh2(S-NTTL)4	c-C6H12	74	2.2:1	29	56
10	Me	Rh2(S-PTAD)4	c-C6H12	79	1.4:1	41	54
11	Me	Rh2(R-BPTV)4	c-C6H12	76	1:1.1	∼43	∼80
12	Me	Rh2(S-biTISP)4	c-C6H12	78	1:1.4	∼10	38
13	Me	Rh2(S-BTPCP)4	c-C6H12	65	3.8:1	∼36	∼11
14	Me	Rh2(R-DPCP)4	c-C6H12	74	1:1.1	19	∼18
15	Me	Rh2(S-DOSP)4	c-C6H12	71	1.0:1	<5	7
16	Me	Rh2(S-BNP)4	c-C6H12	73	1.9:1	∼19	∼45
17	t-Bu	Rh2(S-BTPCP)4	c-C6H12	77	2.8:1	42	63
18	t-Bu	Rh2(S-biTISP)2	c-C6H12	77	2.5:1	∼46	46
19	t-Bu	Rh2(S-BNP)4	c-C6H12	83	3.3:1	13	24

^aDiastereomer ratios determined by ¹H NMR analysis of crude reaction mixture. Enantiomeric excesses were determined by HPLC analysis.

^bCombined isolated yield of cis-12 and trans-12.