Table 2.

Examination of grinding auxiliaries on yield of 3aa.^a

Entry	Grinding auxiliary	Weight (g)	Yield (%)
1	silica-gel	5	84 (n.r.)b
2	NaCl	5	54
3	α-Al2O3 (base)	5	68
4	γ-Al2O3(neutral)	5	61
5	MgAl-LDHs	5	72 (n.r.)c
6	silica-gel	3	74
7	silica-gel	7	70

^aReaction conditions unless otherwise noted: 1a (1.5 mmol), 2a (2.1 mmol), Pd/MgAl-LDHs (2.5 mol %), TBAB (1.5 mmol), K₂CO₃ (3.6 mmol), grinding auxiliary were placed in a 80 mL stainless-steel vessel (Φ_MB = 0.25, d_MB = 5 mm). HSBM conditions: 60 min at 800 rpm. ^bSilica gel used as grinding auxiliary without Pd/MgAl-LDHs catalyst. ^cMgAl-LDHs used as grinding auxiliary without Pd/MgAl-LDHs catalyst.