A norbornene-mediated palladium-catalyzed sequence is described in which an alkyl-aryl bond and an aryl-heteroaryl bond are formed in one reaction vessel. The aryl-heteroaryl bond-forming step occurs via a direct arylation reaction. A number of six-, seven-, and eight-membered ring-annulated indoles, pyrroles, pyrazoles, and azaindoles were synthesized from the corresponding bromoalkyl azole an...

A system capable of performing both DNA-templated chemical reactions and detection of bond formations is reported. Photocleavable DNA templates direct reactions. Products from bond-forming events re-ligate original templates, amplifiable by PCR, therefore distinguishing bond formation from background. This system provides a novel approach for discovering potential new chemical reactions.

The study of pollution due to combined antibiotics and metals is urgently needed. Photochemical processes are an important transformation pathway for antibiotics in the environment. The mechanisms underlying the effects of metal-ion complexation on the aquatic photochemical transformation of antibiotics in different dissociation forms are crucial problems in science, and beg solutions. Herein, ...

BACKGROUND Orthodontists are commonly faced with the decision of what to do with debonded or inaccurately positioned brackets. An economical option to this dilemma is to recycle the brackets. Many recycling methods have been proposed, but the optimal bond strength of these recycled brackets needs further evaluation. Objectives: To evaluate and compare the effect of three recycling methods: (i) ...

We review the continuous{time literature on the so{called direct approach to bond option pricing. Going back to Ball and Torous (1983), this approach models bond price processes directly (i.e. without reference to interest rates or state variable processes) and applies methods that Black and Scholes (1973) and Merton (1973) had originally developed for stock options. We describe the principal m...

Introduction: Porcelain fracture is a relatively common problem in clinical dental practice. Various methods have been proposed for repairing porcelain fractures including direct composite resin repair or construction of a porcelain laminate veneer and its cementation with a resin cement. Evaluation of shear bond strength of porcelain repair methods was the purpose of this study. Methods: Tw...

The bond energy (BE) of CC in CH3-CH3 with respect to geometry frozen fragments follows a sigmoidal increase as function the θ = HCC pyramidalization angle. Using dynamic orbital forces BE index, same behaviour unique 〈θ〉 parameter, mean angle substituents, is found for 24 single bonds various hydrocarbons. Thus parameter appears straightforward and robust index geometrical constraints which ca...

Three types of direct-bonding metal bases were used to determine the effect of five commercial surface treatments on in vitro tensile bond strength. The proprietary treatments were etching, silanation, surface activation, etching plus silanation, and etching plus surface activation. Nontreatment was used as a control. The bases were of the mesh, photo-etched, and grooved types. Bases were loade...

The biaryl structural motif is a predominant feature in many pharmaceutically relevant and biologically active compounds. As a result, for over a century1 organic chemists have sought to develop new and more efficient aryl-aryl bond-forming methods. Although there exist a variety of routes for the construction of aryl-aryl bonds, arguably the most common method is through the use of transition-...