Premium
Palladium(II)‐Catalyzed Sp 3 /Sp 2 γ ‐ and δ ‐C‐H Functionalization of Aryl Amines using 5‐Methylisoxazole‐3‐Carboxamide as Directing Group
Author(s) -
Singh Prabhakar,
Dalal Arup,
Babu Srinivasarao Arulananda
Publication year - 2019
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.201900132
Subject(s) - chemistry , mica , catalysis , surface modification , aryl , palladium , functional group , carboxamide , medicinal chemistry , molecule , combinatorial chemistry , stereochemistry , organic chemistry , materials science , alkyl , polymer , composite material
A dual objective‐based study comprising exploration of 5‐methylisoxazole‐3‐carboxamide (MICA) as a directing group (DG) for the Pd(II)‐catalyzed sp 3 /sp 2 γ ‐ and δ ‐C−H activation/functionalization of aryl amines and assembling of various MICA motifs are reported. The Pd(II)‐catalyzed MICA‐aided γ ‐C(sp 3 )‐H arylation/acetoxylation of ortho ‐toluidines gave various 2‐aminodiphenylmethanes and 2‐aminobenzyl acetates, respectively. The Pd(II)‐catalyzed MICA‐aided γ ‐C(sp 2 )‐H arylation/acetoxylation of benzylamines gave the corresponding arylated/acetoxylated products. Furthermore, the Pd(II)‐catalyzed MICA‐aided δ ‐C(sp 2 )‐H amidation/alkenylation of phenethylamines were also explored. Representative control reactions were done to assess the relative effectiveness of MICA for the γ ‐C(sp 3 )‐H arylation and MICA is a removable DG. Apart from the usage of MICA as a DG for the sp 2 /sp 3 C−H functionalization of aryl amines, indirectly this process has led to the construction of a library of MICA motifs. This is an added advantage to note as the MICA‐based motifs are valuable small molecules in medicinal chemistry.