405238-15-5

Upstream product

• 2253-73-8 isopropyl isothiocyanate 
• 822-67-3 Cyclohex-2-enol 

Downstream Products

• 491880-02-5 rac-S-cyclohex-2-enyl N-isopropylmonothiocarbamate 
• 255851-54-8 isopropyl-thiocarbamic acid S-((S)-cyclohex-2-enyl) ester 
• 255851-58-2 (R)-S-cyclohex-2-enyl N-isopropylmonothiocarbamate 

Relevant academic research and scientific papers

The synthesis and configurational stability of enantioenriched α-thioallyllithium compounds and the stereochemical course of their electrophilic substitution

Deprotonation of enantioenriched S-allyl N-monoalkylmonothiocarbamates furnished the corresponding chiral lithium compounds. The α-thioallyllithium compounds 9 and 25 were found to be configurationally stable in THF solutions at -78 °C. These represent the first configurationally stable α-thio-substituted allyllithium compounds, and they can be utilized in asymmetric synthesis. Alkylations proceeded with stereo-inversion or in an anti-SE′ process, while addition to carbonyl compounds took place in a syn-SE′ process. Hydroxyalkylation products were employed as starting material for Ni0-catalyzed cross-coupling reactions.

Palladium(0)-catalyzed enantioselective O,S-rearrangement of racemic O-allylic thiocarbamates: A new entry to enantioenriched allylic sulfur compounds

Reaction of (±)-(E)-pent-3-en-2-ol, (±)-(E)-hept-4-en-3-ol, (±)-(E)-2,6-dimethylhept-4-en-3-ol, (±)-cyclohex-2-en-1-ol, and (±)-cyclohept-2-en-1-ol with methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, and benzyl isothiocyanate gave the corresponding racemic O-allylic thiocarbamates of medium to good thermal stability in good yields. The palladium(0)-catalyzed rearrangement of the (±)-(E)-pent-3-en-2-ol-, (±)-(E)-hept-4-en-3-ol-, (±)-cyclohex-2-en-1-ol-, and (±)-cyclohept-2-en-1-ol-derived O-allylic thiocarbamates at room temperature in methylene chloride by using Pd2(dba)3·CHCl3 (dba = dibenzylideneacetone) as precatalyst and (+)-(1R,2R)-1,2-bis-N-((2-(diphenylphosphino)benzoyl)-1,2-diaminocyclohexane as ligand for the palladium atom proceeded quantitatively and gave the corresponding acyclic (R)-configured S-allylic thiocarbamates and the cyclic (S)-configured S-allylic thiocarbamates with ee values ranging from 85% to ≥99% in yields of 76-94%. Rearrangement of the O-allylic thiocarbamates carrying a methyl group at the N atom not only was the fastest but also proceeded with the highest enantioselectivity. No rearrangement was observed under these conditions in the case of the racemic N-methyl O-allylic thiocarbamate derived from (±)-2,6-dimethylhept-4-en-3-ol, which has a branched carbon skeleton. (S)-Cyclohex-2-enethiol of 97% ee was obtained through hydrolysis of the corresponding N-methyl S-allylic thiocarbamate. 2-((R)-(E)-1-Methylbut-2-enylsulfanyl)pyrimidine of 91% ee and 2-((S)-cyclohex-2-enylsulfanyl)pyrimidine of 97% ee were synthesized in one synthetic operation from the corresponding N-methyl S-allylic thiocarbamates and 2-chloropyrimidine. Similarly, (S)-cyclohex-2-enylsulfanyl)benzene of 97% ee was obtained in one synthetic operation from the corresponding N-methyl S-allylic thiocarbamate through a palladium(0)-catalyzed substitution of iodobenzene in the presence of a base. The palladium(0)-catalyzed enantioselective rearrangement of O-allylic carbamates to S-allylic carbamates has been extended from the solution phase to the solid phase by using a methyl thioisocyanate polystyrene resin. In the case investigated the enantioselectivity of the rearrangement on the solid phase was considerably lower than that in solution.