Periodic Reporting for period 1 - DiPipe (Direct remote C-H functionalization in piperidine derivatives)
Reporting period: 2019-04-01 to 2021-03-31
We also developed an efficient strategy for the cleavage of the picolinamide directing group (DG) and recycling of the byproduct. In this protocol, picolinamides were first Boc activated into tertiary N-Boc-N-substituted picolinamides. These were then cleaved via a Ni-catalyzed esterification reaction with EtOH to give valuable N-Boc protected amines. Ni(cod)2 was used as a catalyst without any ligands or base additives. The byproduct, ethyl 2-picolinate can be used to install the picolinamide DG in a direct or indirect manner on amines. The protocol exhibits a broad functional group tolerance and high yields. To demonstrate the utility of this approach, it was applied on many selected examples from the recent C−H functionalization literature featuring 2-picolinamide as a DG.
As a major dissemination result, one scientific publication has already been published. Another manuscript was submitted in Angew. Chem. Int. Ed. on 19th May, 2021. In order to communicate about the project to the public, a project blog on a social media was maintained (https://www.facebook.com/groups/dipipe). A video was published on YouTube (https://www.youtube.com/watch?v=45UO_TF4204&ab_channel=SovanBiswas). Both these actions target broad public and university students as well as broad (beyond the organic chemistry) research community.