Visible-light photocatalysis has evolved over the last decade into a widely used method in organic synthesis. Photocatalytic variants have been reported for many important transformations, such as cross-coupling reactions, α-amino functionalizations, cycloadditions, ATRA reactions, or fluorinations. To help chemists select photocatalytic methods for their synthesis, we compare in this Review classical and photocatalytic procedures for selected classes of reactions and highlight their advantages and limitations. In many cases, the photocatalytic reactions proceed under milder reaction conditions, typically at room temperature, and stoichiometric reagents are replaced by simple oxidants or reductants, such as air, oxygen, or amines. Does visible-light photocatalysis make a difference in organic synthesis? The prospect of shuttling electrons back and forth to substrates and intermediates or to selectively transfer energy through a visible-light-absorbing photocatalyst holds the promise to improve current procedures in radical chemistry and to open up new avenues by accessing reactive species hitherto unknown, especially by merging photocatalysis with organo- or metal catalysis.

Visible-Light Photocatalysis: Does It Make a Difference in Organic Synthesis?

From 2000 to mid-2010: a fruitful decade for the synthesis of pyrazoles.

Photokatalyse mit sichtbarem Licht: Welche Bedeutung hat sie für die organische Synthese?

Recent Advances in the Synthesis of Pyrazoles. A Review

The non-steroidal anti-inflammatory drugs (NSAIDs) are diverse group of compounds used for the treatment of inflammation, since the introduction of acetylsalicylic acid in 1899 Traditional (first generation) NSAIDs exert antiinflammatory, analgesic, and antipyretic effects through the blockade of prostaglandin synthesis via non-selective inhibition of cyclooxygenase (COX-1 and COX-2) isozymes Their use is associated with side effects such as gastrointestinal and renal toxicity A number of selective (second generation) COX-2 inhibitors (rofecoxib, celecoxib, valdecoxib etc) were developed as safer NSAIDs with improved gastric safety profile Observation of increased cardiovascular risks in APPROVe (Adenomatous Polyp Prevention on Vioxx) study sent tremors and led to voluntary withdrawn of Vioxx (rofecoxib) by Merck from the market in September 2004 followed by Bextra (valdecoxib) in 2005 raising a question on the safety of selective COX-2 inhibitors This leads to the belief that these effects are mechanism based and may be class effect However, some studies suggested association of traditional NSAIDs with similar effects requiring a relook into the whole class of NSAIDs rather than simply victimizing the selective COX-2 inhibitors Recognition of new avenues for selective COX-2 inhibitors such as cancer, Alzheimer's disease, Parkinson's disease, schizophrenia, major depression, ischemic brain injury and diabetic peripheral nephropathy has kindled the interest in these compounds This review highlights the various structural classes of selective COX-2 inhibitors developed during past seven years (2003-2009) with special emphasis on diaryl-hetero/carbo-cyclic class of compounds Molecular modeling aspects are also briefly discussed

Progress in COX-2 Inhibitors: A Journey So Far

1,3-Diarylcycloalkanopyrazoles and diphenyl hydrazides as selective inhibitors of cyclooxygenase-2.

Novel 1,3-diarylcycloalkanopyrazoles 1, and diphenyl hydrazides 2 were identified as selective inhibitors of cyclooxygenase-2. The 1,3-diaryl substitution pattern of the pyrazole ring in 1 differentiates these compounds from most of the known selective COX-2 inhibitors that contain two aryl rings at the adjacent positions on a heterocyclic or a phenyl ring. Similarly, the two phenyl rings in 2 are also separated by three atoms. SAR of both phenyl rings in 1 and 2, and the aliphatic ring in 1 will be discussed.

Dave M. Ritchie

Papers

1,3-Diarylcycloalkanopyrazoles and diphenyl hydrazides as selective inhibitors of cyclooxygenase-2.

1,3-Diarylcycloalkanopyrazoles and Diphenyl Hydrazides as Selective Inhibitors of Cyclooxygenase-2.