Table 1 Pd-catalysed carbonylative annulation of acylsilane 1a and imine 2a

From: Catalytic synthesis of β-lactam derivatives by carbonylative cycloaddition of acylsilanes with imines via a palladium Fischer-carbene intermediate

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Entry

Deviation from entry 1

Yield (%)a,b

3aa

Recovered 2a

4

1

None

40 (4.3:1)

56

9

2

No CO

48 (4.2:1)

54

30

3

No CO with IPr* instead of IPr

93 (6.4:1)

5

65

4c

No palladium with IPr* instead of IPr

0

76

0

5d

No CO under dark conditions with IPr* instead of IPr

88 (6.4:1)

9

69

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  1. a1a (0.60 mmol), 2a (0.20 mmol), Pd2(dba)3 (0.010 mmol), IPr (0.020 mmol) and toluene (0.60 ml) in COware at 110 °C for 17 h. CO was generated from p-methoxyphenyl formate and Et3N. For details of COware, see Supplementary Tables 4–6. bYields were determined by GC or NMR analysis. Stereoisomeric ratio is shown in the parentheses. cRun at 160 °C. dThe reaction was performed in the absence of any light by covering the reaction vessel with aluminium foil.
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