Catalytic C(sp
<sup>3</sup>
)−H Arylation of Free Primary Amines with an
<i>exo</i>
Directing Group Generated In Situ
作者:Yan Xu、Michael C. Young、Chengpeng Wang、David M. Magness、Guangbin Dong
DOI:10.1002/anie.201604268
日期:2016.7.25
Herein, we report the palladium‐catalyzeddirectarylation of unactivated aliphatic C−H bonds in free primary amines. This method takes advantage of an exo‐imine‐type directing group (DG) that can be generated and removed in situ. A range of unprotected aliphatic amines are suitable substrates, undergoing site‐selective arylation at the γ‐position. Methyl as well as cyclic and acyclic methylene groups
The invention relates to a method for producing amides or esters from carboxylic acids and from an amine constituent or alcohol constituent in the presence of a 1,3,5-triazine and optionally in the presence of an organic solvent and of a tertiary amine. According to the invention, a (bi)cyclic diamine or an adduct formed therefrom with the triazine constituent is used as a tertiary amine in a preferred stoichiometric ratio of diamine to the triazine constituent ranging from 0.30 to 1.10; the stoichiometric ratio of carboxylic acid to the amine constituent or alcohol constituent should range from 0.2 to 5.0, and; the molar ratio of carboxylic acid to the triazine constituent ranges from 0.5 to 1.5. Amino acids such as N-protected amino acids and peptides serve as carboxylic acid constituents and (C-protected) amino acids or a C-protected peptide serve as the amine constituent. 2-chlorine-4,6-dimethoxy-1,3,5-triazine (CDMT) is used as the preferred 1,3,5-triazine, and the N,N′-dimethyl-1,4-piperazine is used as the cyclic diamine. In addition to this method, which can be carried out at temperatures ranging from −80 to +150 ° C. and in the presence of an organic solvent, the invention also relates to adducts comprised of (bi)cyclic diamine and 1,3,5-triazine. Compared to the prior art, higher yields with shorter reaction times are achieved using the described method, and distinctly smaller waste quantities of tertiary amine bases accrue.