Table 3.
Entry | Conditions | R | Result |
---|---|---|---|
1 | CH2C(OZnBr)OtBu, Pd2(dba)3/dppf, THF | CH2CO2tBu | 18a (decomp.) |
2 | CH2C(OSnnBu3)OEt, PdCl2(P(o-tol)3)2, CuF2 | CH2CO2Et | 18b (N.R.) |
3 | nBu3SnCH=CH2, Pd(PPh3)4, CuI | CH=CH2 | 18c (< 5%) |
4 | nBu3SnCH=CH(OEt), Pd(PPh3)4, CuCl, LiCl, THF | CH=CH(OEt) | 18d (67%) |
5 | nBu3SnCH=C(OEt)2, Pd(PPh3)4, CuCl, LiCl, THF | CH=C(OEt)2 | 19 (0–40%) |
6 | nBu3SnCH=C(OEt)2, Pd(PPh3)4, CuTC, THF | CH=C(OEt)2 | 19 (60%) |
CuTC = Copper (I) thiophene-2-carboxylate.