75540-86-2Relevant academic research and scientific papers
GENERATION OF sec-THIOAMIDE DIANIONS AND THEIR REGIOSELECTIVE REACTION WITH ELECTROPHILES.
Tamaru, Y.,Kagotani, M.,Furukawa, Y.,Amino, Y.,Yoshida, Z.
, p. 3413 - 3416 (2007/10/02)
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-dimethylthioacrylamide and N-methylthiocyclohexenecarboxamide.
Cycloaddition Reactions of Heterocumulenes, XIX. 1:1-, 2:1-, and 1:2-Cycloadducts from the Reaction of Thioketenes with Azomethines
Schaumann, Ernst,Ehlers, Joern,Grabley, Fritz-Feo
, p. 3010 - 3023 (2007/10/02)
The reaction of the thioketenes 1a-e with the azomethines 2a, b affords 1:1-, 2:1-, and 1:2-cycloadducts (2-azetidinethiones 3, dihydro-4H-1,3,5-dithiazines 5, and hexahydro-4-pyrimidinethiones 9).From allylthioketenes 15 and 2a-d, 19 the corresponding cycloadducts 16, 17, and 18 are isolated.On pyrolysis of the 4-alkylthiadiazoles 13 in the azomethine 2d the liberated aldothioketenes 1f, g are trapped by 2d to give the β-thiolactams 3e, f.The 1:1-adducts 3, 16 are formed in the sterically favoured configuration A (for 16a: B), unless sterically extremely hindered thioketenes are the starting materials (16f, g) or steric interactions of the substituents on C-3, C-4 are comparable (3b, 16h) or negligible (3e).For the heterocycles 5a, b geometrical isomerism at the exocyclic C=C bond on C-2 is detected.Formation of products 5, 9, 17, 18 and the stereochemistry of 3, 16 can be understood in terms of the dipolar intermediate 20.
