While tertiary boranes undergo efficient protodeboronation with carboxylic acids, tertiary boronic esters do not. Instead, we have discovered that CsF with 1.1 equiv of H2O (on tertiary diarylalkyl boronic esters) or TBAF·3H2O (on tertiary aryldialkyl boronic esters) effect highly efficient protodeboronation of tertiary boronic esters with essentially complete retention of configuration. Furthe...

A new method for the electrophilic α-alkynylation of ketones was developed using hypervalent iodine under mild and metal-free conditions. Carbonyl compounds containing an α-acetylene group were obtained in good to excellent yields for several ketones using 1-[(trimethylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one (TMS-EBX) as an alkynylation agent in the presence of t-BuOK and TBAF in THF as solven...

Upon treatment with tetrabutylammonium fluoride (TBAF), [32]heptaphyrins 1 and 2 underwent conformational changes to form Möbius aromatic species, as indicated by the appearance of sharp and intense B-like bands and distinct Q-like bands, long-lived S1-states, and relatively large TPA cross-section values. Hence, deprotonation has been shown to be an additional effective means to induce the for...

A versatile synthesis of 1,2,3-triazolyl-4-phosphines from the borane complexes of phosphino-alkynes is reported. The efficiency of the procedure relies on the use of readily available silyl-protected alkynylphosphine-boranes, which were subjected to desilylation with TBAF followed by copper-catalyzed azide-alkyne-cycloaddition in one pot. Subsequent treatment with DABCO afforded the targeted t...

Because of the synergy seen in adult trials when 5-fluorouracil is combined with leucovorin, we initiated a Phase I trial of this combination in children's refractory cancer. Leucovorin, an equal mixture of the (6/i,,S")-diastereoisomers, was administered p.o. for 6 consecutive days as 4 equal doses at 0, 1, 2, and 3 h totaling 500 mg/m2/day. 5-Fluorouracil was given daily on days 2 to 6 as an ...

Fluoride anion was demonstrated as a superior activator of elemental sulfur (S8) to perform sulfurization thioketones leading diverse sulfur-rich heterocycles. Due solubility problems, reactions must be carried out either in THF using tetrabutylammonium fluoride (TBAF) or DMF cesium (CsF), respectively. The reactive sulfurizing reagents are situ generated, nucleophilic fluoropolysulfide anions ...

The electrochemical generation of vinyl carbocations from alkenyl boronic esters and boronates is reported. Using easy-to-handle nucleophilic fluoride reagents, these intermediates are trapped to form fully substituted fluorides. Mechanistic studies support the formation dicoordinated through sequential single-electron oxidation events. Notably, this fluorination features fast reaction times Le...

A new series of indole-based pyranoquinoline derivatives P1-24 has been synthesized by a one-pot cyclocondensation reaction of 2-(4-substituted)phenyl-N-allyl-indole-3-carbaldehydes 1a-d; active methylenes 2a-c; and 4-hydroxy-1-substituted quinolin-2(1H)-one 3a-b catalysed by an organocatalyst tetra-n-butylammonium fluoride (TBAF) in aqueous ethanol. The easy experimental procedure of the react...

Hydrosilylation reaction of various fluoroalkylated alkynes with Et(3)SiH in the presence of a catalytic amount of Co(2)(CO)(8) was investigated. The hydrosilylation of the alkynes having fluoroalkyl and aryl groups took place smoothly with good regioselectivity (ca. 80:20). In sharp contrast, the reaction of the alkynes having a fluoroalkyl group and a benzyl-type substituent, or various propa...