Trideuteromethylation in dimethyl sulphoxide

Combined Approach of Backbone Amide Linking and On-Resin N-Methylation for the Synthesis of Bioactive and Metabolically Stable Peptides

“…If both reagents (MeI and LiO t Bu) were increased up to 20 equiv, the conversion raised up to 73.7% in only a single treatment of each step for 5 min. Furthermore, if the reaction time is increased up to 60 min, for deprotonation and methylation, the conversion is >90% in just a single treatment. , Additionally, it became clear that DMSO has to be added as it is described as an efficient solvent for methylation. , In total, 32 experiments were performed and interpreted in a design of experiment (DOE). A DOE provides information about the interaction of different factors and thus how the total system, here on-resin alkylation, works.…”

“…14,16 Additionally, it became clear that DMSO has to be added as it is described as an efficient solvent for methylation. 17,18 In total, 32 experiments were performed and interpreted in a design of experiment (DOE). A DOE provides information about the interaction of different factors and thus how the total system, here on-resin alkylation, works.…”

The preparation of a solubilized form of Lawessons reagent and its thionation reactions

“…The 2-tert-butylanisole was made in good yield by the methylation of 2-tert-butylphenol in DMSO using Mel/NaOH [13,14]. The presence of dithiophosphine ylides in solution can be demonstrated by 31 P-{ 1 H} NMR spectroscopy on a mixture of Fc 2 P 2 S 4 and LR*, which results in an AX-type spectrum (d P ‫ס‬ 16.2, 17.4 ppm, J{ 31 P-31 P} 7 Hz) indicating the formation of Fc*P(S)S 2 P(S)R [R ‫ס‬ MeOBuC 6 H 3 ].…”

Broadening of horizons in the synthesis of CD3-labeled molecules

“…Classical approaches to O-trideuteromethylation generally involve nucleophilic attack of Onucleophiles with electrophilic CD3 reagents under strongly basic conditions [108][109][110][111] or acidic conditions. 112 Due to the toxicity associated with the commonly used electrophilic CD3 reagents such as CD3I, (CD3)2SO4, and deuterated diazomethane, there is a strong need for the development of novel O-trideuteromethylation methods employing less toxic trideuteromethylating reagents.…”