title: Regio- and stereoselective Pd-catalyzed direct arylation of unactivated sp(3) C(3)-H bonds of tetrahydrofuran and 1,4-benzodioxane systems.
abstract: An auxiliary-enabled Pd-catalyzed highly regio- and stereoselective sp(3) C-H activation and the direct arylation of the C3-position of oxygen heterocycles, such as tetrahydrofuran and 1,4-benzodioxane systems, are reported. An efficient stereoselective construction of cis 2,3-disubstituted tetrahydrofuran derivatives (analogues of norlignans) and cis 2,3-disubstituted 1,4-benzodioxane derivatives (analogues of neolignans) is described. The direct C(sp(3))-H arylation of the C3-position of (R)- or (S)- tetrahydrofuran-2-carboxamides furnished the corresponding (2R,3R) and (2S,3S) C3-arylated THF scaffolds as major compounds with very high regio- and diastereoselectivities. The stereochemistry of the products obtained in this work were unambiguously assigned on the basis of the X-ray structure analyses of representative compounds 3b, 3e, 4p, and 7.
authors.affiliation: Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Manauli P.O., Sector 81, SAS Nagar, Mohali, Knowledge City, Punjab 140306, India.
authors.forename: Ramarao
authors.initials: R
authors.lastname: Parella
authors.forename: Srinivasarao Arulananda
authors.initials: SA
authors.lastname: Babu
mesh_terms: D002384:Catalysis; D004146:Dioxanes / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D004146:Dioxanes; D005663:Furans; D009942:Organometallic Compounds; C018674:tetrahydrofuran; D010165:Palladium; C527681:1,4-benzodioxan