title: Rhodium-catalyzed B-H activation of 1,2-azaborines: synthesis and characterization of BN isosteres of stilbenes.
abstract: The first example of catalytic B-H activation of azaborines leading to a new family of stilbene derivatives through dehydrogenative borylation is reported. Ten 1,2-azaborine-based BN isosteres of stilbenes have been synthesized using this method, including a BN isostere of a biologically active stilbene. It is demonstrated that BN/CC isosterism in the context of stilbenes can lead to significant changes in the observed photophysical properties such as higher quantum yield and a larger Stokes shift. Direct comparative analysis of BN stilbene 3g and its carbonaceous counterpart 6g is consistent with a stronger charge-transfer character of the excited state exhibited by 3g in which the 1,2-azaborine heterocycle serves as a better electron donor than the corresponding arene.
authors.affiliation: Department of Chemistry, Boston College , Chestnut Hill, Massachusetts 02467, United States.
authors.forename: Alec N
authors.initials: AN
authors.lastname: Brown
authors.forename: Lev N
authors.initials: LN
authors.lastname: Zakharov
authors.forename: Tanya
authors.initials: T
authors.lastname: Mikulas
authors.forename: David A
authors.initials: DA
authors.lastname: Dixon
authors.forename: Shih-Yuan
authors.initials: SY
authors.lastname: Liu
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*; D013267:Stilbenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C556261:1,2-azaborine; D001372:Aza Compounds; D001896:Boron Compounds; D013267:Stilbenes; D012238:Rhodium