title: 4-Amino-2,1,3-benzothiadiazole as a Removable Bidentate Directing Group for the Pd(II)-Catalyzed Arylation/Oxygenation of sp2/sp3β-C-H Bonds of Carboxamides.
abstract: In this paper, we report 4-amino-2,1,3-benzothiadiazole (ABTD) as a new bidentate directing group for the Pd(II)-catalyzed sp2/sp3C-H activation/functionalization of various aliphatic/alicyclic/aromatic carboxamide systems. The Pd(II)-catalyzed, ABTD-directed sp3C-H arylation/acetoxylation of aliphatic- and alicyclic carboxamides afforded the corresponding β-C-H arylated/acetoxylated carboxamides. The Pd(II)-catalyzed, ABTD-directed sp3C-H arylation of cyclobutanecarboxamide with different aryl iodides afforded the corresponding bis β-C-H arylated cyclobutanecarboxamides having all-cis stereochemistry with a high degree of stereocontrol. The Pd(II)-catalyzed, ABTD-directed arylation/benzylation/acetoxylation/alkoxylation of ortho C(sp2)-H bonds of various benzamides afforded the corresponding ortho C-H arylated/benzylated/oxygenated benzamides. The observed regio- and stereoselectivity in the Pd(II)-catalyzed, ABTD-directed arylation/benzylation of aliphatic/alicyclic carboxamides and benzamides were ascertained from the X-ray structures of representative compounds 5g (bis-β-C(sp3)-H arylated cyclobutanecarboxamide) and 7f (ortho C(sp2)-H arylated benzamide). A brief description on the efficiency, scope, and limitations of bidentate directing group ABTD is reported.
authors.affiliation: Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Manauli P.O., Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India.
authors.forename: Chennakesava
authors.initials: C
authors.lastname: Reddy
authors.affiliation: Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Manauli P.O., Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India.
authors.forename: Narendra
authors.initials: N
authors.lastname: Bisht
authors.affiliation: Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Manauli P.O., Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India.
authors.forename: Ramarao
authors.initials: R
authors.lastname: Parella
authors.affiliation: Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Manauli P.O., Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India.
authors.forename: Srinivasarao Arulananda
authors.identifier: 0000-0002-1795-8843
authors.initials: SA
authors.lastname: Babu