Batch and Continuous-Flow One-Pot Processes using Amine Diazotization to Produce Silylated Diazo Reagents

A novel synthesis of trimethylsilyldiazomethane (TMSCHN2) by diazotization of trimethylsilylmethylamine (TMSCH2NH2) is reported using batch and continuous flow synthesis. The latter affords a daily production of 275 g (2.4 mol) of TMSCHN2. Other silylated methylamines were also successfully reacted under the developed reaction conditions to furnish various silicon-bearing diazomethane reagents. The applicability of the process is highlighted by disclosure of batch and continuous flow one-pot esterification and 1,3-dipolar cycloaddition processes. Furthermore, the high-yielding esterification of carboxylic acids with silylated and substituted methylamines in continuous flow is disclosed. Finally, work-up and purification procedures are reported for the preparation of a 2-MeTHF solution of TMSCHN2, which can be used in rhodium-catalyzed methylenation and homologation reactions.