Hydrocarbonation and Hydroamination

Two products 186 and 187 are obtained by the addition of carbon pronucleophiles (Nu-H) by the eleavage of both distal and proximal bonds in 185. These reactions look somewhat complicated and their mechanisms are not easily understood. 

Reaction of MCP 179 with deuterated methylmalononitrile (188) catalyzed by Pd(PPh3)4 gave rise to the proximal bond cleavage product 189 in 86% yield, which is deuterated at C-2 exclusively. This product corresponds to 187 [58]. The reaction of 179 with 188 starts by the addition of Nu-Pd-D to the methylene bond to generate the cyclopropylcarbinylpalladium 190, which is converted to 191 by jS-carbon elimination, llien the rather unusual rearrangement of 191 to the r-allylpalladium intermediate 192 takes place. The rearrangement can be understood by elimination of H-Pd-Nu from 191 and readdition. Then reductive elimination provides 189. 

On the other hand, addition of methylmalononitrile (188) to the MCP 193 gave the distal bond cleavage product 194 in 82% yield, which is deuterated at the C-3 position. Obviously, the product 194 corresponds to 186. The reaction starts from the addition product 195, which is converted to the allylpalladium 196 by -carbon elimination, and then to the rr-allylpalladium intermediate 197. The final product 194 is obtained from 197. 

Ketones are allylated with MCPs using Pd(PPh3)4 as a catalyst under neutral conditions [59]. Reaction of acetophenone (199) with MCP 198 afforded the allylated acetophenone 200 in 79 % yield. The reaction is understood by the generation of H-Pd-CH2COPh under neutral conditions, and the addition to form 201. The 

The distal bond cleavage occurs in hydroamination. Reaction of MCP 208 with dibenzylamine afforded the allylic amine 209 by using the combination of 7r-allylpalladium chloride with DPPP as a catalyst [61]. Similarly sulfonamide 211 was allylated with MCP 210 to produce the diallylated amide 212 using a complex mixture of Pd(0), Pd(II), and PPhs as a catalyst [62]. The use of Pd(0)-PPh3 in an appropriate ratio seems to be effective. 

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