Table 1 Optimization of the XEC of alkynyl sulfide with TMSCl

From: Cobalt-catalyzed cross-electrophile coupling of alkynyl sulfides with unactivated chlorosilanes

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Entry

Variation from standard conditions[a]

Yield of 3a [%][b]

Yield of 1a-1 [%][b]

1

none

87(85)

n.d.

2

CoCl2 or CoBr2 as catalyst

69 or 73

n.d.

3

Co(acac)2 as catalyst

70

trace

4

NiI2 or CrCl2 as catalyst

45 or 29

19 or 37

5

Fe(acac)2 as catalyst

n.d.

n.d.

6

MeCN or THF as solvent

trace

13 or 31

7

Mn instead of Zn

n.d.

trace

8

Mn instead of Zn, ZnI2 (1 equiv)

67

n.d.

9

w/o CoI2 or Zn or L8 (tpy)

n.d.

n.d.

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  1. [a] Reaction conditions: 1a (0.1 mmol), TMSCl (0.2 mmol), CoI2 (10 mol%), L8 (15 mol%), Zn (2.0 equiv), DMF (1.0 mL), rt, 4 h. [b] The yields were determined by GC using dodecane as the internal standard; Isolated yield was shown in parentheses; n.d. = no detected; w/o = without.
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