B(3,4,5-FHC) Lewis acid-catalysed C3-allylation of indoles.

Herein we report the B(3,4,5-FHC)-catalysed C3-allylation of indoles using allylic esters. 25 examples of C3-allylated products are presented in up to 97% yield. The mechanism for the reaction was explored using detailed Density Functional Theory (DFT) studies.

Synthesis and lewis acidity of fluorinated triaryl borates.

A series of fluorinated triaryl borates B(OAr) (Ar = 2-FCH, 3-FCH, 4-FCH, 2,4-FCH, 3,5-FCH, 2,3,4-FCH, 2,4,6-FCH, 3,4,5-FCH) have been prepared and isolated from the reactions of the mono-, di-, or tri-fluorophenol with BCl. The Lewis acidity of these borates has been determined by NMR spectroscopic and theoretical methods and compared to their well-established borane counterpart.

Late-stage derivatization of a (B,O)-doped perylene.

Regioselective di- and tetrabrominations of the (B,O)-perylene 1 afford derivatives 2-4. Despite their poor solubility, 2 and 4 could be used in Stille-type coupling reactions to introduce two CCMe (5) or four CC(-CHBu) substituents (6), respectively. The alkynylated derivatives show blue-green photoluminescence with appreciable quantum efficiencies.

Borane promoted aryl transfer reaction for the synthesis of α-aryl functionalised β-hydroxy and β-keto esters.

The synthesis of a series of α-aryl or α-alkyl functionalised β-hydroxy and β-keto esters has been achieved by reacting α-diazoesters with boranes, and aldehydes, ketones, anhydrides, nitriles, esters or isocyanates. In a mild reaction protocol, 26 examples are presented in yields up to 73%.

One tool to bring them all: Au-catalyzed synthesis of B,O- and B,N-doped PAHs from boronic and borinic acids.

The isoelectronic replacement of C[double bond, length as m-dash]C bonds with B[double bond, length as m-dash]N bonds in polycyclic aromatic hydrocarbons (PAHs) is a widely used tool to prepare novel optoelectronic materials. Far less well explored are corresponding B,O-doped PAHs, although they have a similarly high application potential. We herein report on the modular synthesis of B,N- and B,O-doped PAHs through the [Au(PPh)NTf]-catalyzed 6--dig cyclization of BN-H and BO-H bonds across suitably positioned C[triple bond, length as m-dash]C bonds in the key step.

Introducing Perylene as a New Member to the Azaborine Family.

Substitutional doping of perylene with two boron atoms at the 6b/12b positions and two oxygen or nitrogen atoms at the 1/7 positions has been achieved. The modular synthesis route developed for these bis-BO- (3) and bis-BN-perylenes (5) starts from the readily accessible borinic acid derivative of the doubly brominated 9,10-dihydro-9,10-diboraanthracene (DBA), 1,5-Br DBA(OH) . A Stille-type reaction first furnishes the alkynyl-substituted species 1,5-(RCC) DBA(OH) (2), which undergo double ring closure to afford 3 via the gold-catalyzed addition of the O-H bonds to the C≡C bonds.