Table 1.

Optimisation for the carbonylation of ortho-substituted substrates in flow.

Entry	Ligand	Temperature (°C)	CO pressure (bar)	Conversion (%)	Isolated yield of 5 (%)
1	X-Phos	110	5	68	31
2	S-Phos	110	5	43	36
3	DPPB	110	5	90	38
4	Xantphos	110	5	57	36
5	PPh3	110	5	44	36
6a	PPh3	110	5	59	36
7b	PPh3	110	5	80	33
8c	PPh3	110	5	N/D	18
9	PPh3	100	5	41	31
10	PPh3	120	5	60	37
11	PPh3	130	5	N/D	33
12d	PPh3	110	10	67	46
13d	PPh3	110	15	74	62
14d,e	PPh3	110	15	N/D	31
15f	PPh3	110	15	N/D	68
16f,a	PPh3	110	15	99	90
17f,b	PPh3	110	15	99	73

^a1.6 equiv of base. ^b2.0 equiv of base. ^c1.1 equiv of DBU used instead of NEt₃. ^d10 mL reactor was not “tube-in-tube”. ^e20 mol % DMF added. ^f2 × 15 mL “tube-in-tube” reactors used. N/D: not determined.