M. Kagotani

The regioselective S → C and S → N allylic rearrangement of S-allylthioimidate

Abstract The regioselective S → C and S → N allylic rearrangements of S-allylthioimidates are realized by thermolysis (l60∼200°C) or palladium (II) catalysis (l∼l0 mol% in refluxing THF), respectively.

1,4-addition reaction of organometallics to α,β-unsaturated sec-thioamides

Abstract Preparation of α,β-unsaturated thioamides and their reactions (1,4-addition and β′-lithiation) with organometallics are described.

Generation of sec-thioamide dianions and their regioselective reaction with electrophiles.

Abstract The enolates of sec-thioamides 8 , which are generated by three different methods (scheme II and equation 1), are alkylated selectively at the α-carbon to the thiocarbonyl group. The unusual β′-lithiation to provide an intermediate 11 is observed for N-methyl-α, β-dimetylthioacrylamide and N-methyl-thiocyclohexenecarboxamide.

Sulfinate as cocatalyst 2 : Palladium catalyzed dimerization of butadiene with acyloins☆

Abstract Toluenesulfinate serves as a cocatalyst for the selective formation of α-hydroxy α-octa-2,7-dienyl ketones (2, the products of C-C bond formation) in the reaction of palladium catalyzed dimerization of 1,3-butadiene with acyloins, while the same reaction using triphenylphosphine, instead of toluenesulfinate, as a cocatalyst provides a mixture of 2 and 2-oxy octa-2′,7′-dienyl ethers (3, the products of C-O bond formation).

Sulfinate as cocatalyst 3 : Palladium catalyzed dimerization of butadiene with acylamino ketones

Abstract A catalyst generated in situ from PdCl2 (1 mole) and p-CH3C6H4SO2-Na·4H2O (5 mole) promotes the dimerization of butadiene with the incorporation of α-acylamino ketones (1a∼1h) to provide α-acylamino α-(2,7-octadienyl) ketones (2a∼2h) in good yields. This new type of C-C bond forming reaction is not effected by the catalyst of Pd(PPh3)4 except for one example (with 1e).

Anti-Markownikoff 1,2-hydrosulphonylation of 1,3-dienes viaπ-allylpalladium complexes

The reaction of palladium(II) chloride with 1,3-dienes and sodium alkanesulphinates in acetic acid produces di-µ-chloro-bis(1-syn-alkylsulphonylmethyl-π-allyl)dipalladium(II) complexes, which on treatment with dimethylglyoxime in methanol are degradated selectively to γδ-unsaturated sulphone.