A novel iron-catalyzed decarboxylative Csp3-Csp2 coupling of proline derivatives and naphthol.

A novel iron-catalyzed intermolecular decarboxylative Csp(3)-Csp(2) coupling reaction using proline derivatives as starting materials is developed. In this process, a series of potentially useful ligands (tertiary aminonaphthol) for catalysis was obtained.

Copper-catalyzed aerobic phosphonation of sp3 C-H bonds.

An efficient cross-dehydrogenative-coupling (CDC) between sp3 C-H and H-P bonds was developed using copper salt as catalyst and molecular oxygen as terminal oxidant; this new methodology provides an easy access to biologically important alpha-aminophosphonates.

Overexpression of beta-catenin is responsible for the development of portal hypertension during liver cirrhosis.

beta-catenin functions as both a structural protein and a transcriptional activator. In this study, we examined the expression of beta-catenin in human cirrhotic livers, and administered adenoviruses carrying the beta-catenin or DeltaTCF4 genes to cirrhotic rats to investigate the role of beta-catenin in the development of liver cirrhosis development. beta-catenin expression was associated with liver cirrhosis development in cirrhotic human and rat liver.

Water-triggered, counter-anion-controlled, and silver-phosphines complex-catalyzed stereoselective cascade alkynylation/cyclization of terminal alkynes with salicylaldehydes.

A highly efficient alkynylation-cyclization of terminal alkynes with salicylaldehydes leading to substituted 2,3-dihydrobenzofuran-3-ol derivatives was developed by using Cy(3)P-silver complex as catalyst in water. Counter anions in the silver complex proved to be the key factor to Z/E stereoselectivity control. Aurones can also be obtained effectively from the cascade reaction followed by oxidation without further purification.

Site-specific C-functionalization of free-(NH) peptides and glycine derivatives via direct C-H bond functionalization.

A copper-catalyzed alpha-functionalization of glycine derivatives and short peptides with nucleophiles is described. The present method provides ways to introduce functionalities such as aryl, vinyl, alkynyl, or indolyl specifically to the terminal glycine moieties of small peptides, which are normally difficult in peptide modifications. Furthermore, on functionalization, the configurations of other stereocenters in the peptides could be maintained.

Cross-dehydrogenative coupling (CDC): exploring C-C bond formations beyond functional group transformations.

Synthetic chemists aspire both to develop novel chemical reactions and to improve reaction conditions to maximize resource efficiency, energy efficiency, product selectivity, operational simplicity, and environmental health and safety. Carbon-carbon bond formation is a central part of many chemical syntheses, and innovations in these types of reactions will profoundly improve overall synthetic efficiency. This Account describes our work over the past several years to form carbon-carbon bonds directly from two different C-H bonds under oxidative conditions, cross-dehydrogenative coupling (CDC).

Low-valent indium as a catalyst for the allylation of ketones and N-acylhydrazones.

Indium summer: The use of low-valent indium species in organic chemistry was, until quite recently, underdeveloped. Then came reports of indium(I) halides serving as excellent catalysts for the allylation of ketones and N-acylhydrazones with pinacol allylboronates, and more recently of indium(0) being used as a catalyst for the allylation of ketones in water.

Sc(OTf)3-catalyzed direct alkylation of quinolines and pyridines with alkanes.

The Sc(OTf)(3)-catalyzed C-C bond formation by direct alkylation of quinolines and pyridines using simple alkanes was developed. Various alkanes reacted with quinolines and pyridines to give the corresponding alkylation products in 50-91% yields in the presence of tert-butyl peroxide.

Green chemistry for chemical synthesis.

Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

Palladium-catalyzed 1,4-addition of terminal alkynes to unsaturated carbonyl compounds promoted by electron-rich ligands.

The efficient palladium-catalyzed conjugate addition of terminal alkynes to alpha,beta-unsaturated carbonyl compounds has been developed using electron-rich ligands, producing the corresponding gamma,delta-alkynyl ketone and gamma,delta-alkynyl esters in good yields.

Copper-catalyzed oxidative sp3 C-H bond arylation with aryl boronic acids.

An efficient method was developed for arylation of sp(3) C-H bonds using copper bromide as catalyst in absence of directing group with arylboronic acids. The oxidative arylation provides easy access to biologically active tetrahydroisoquinoline derivatives and can either use peroxide or molecular oxygen as oxidant.

Fluorous tagging: an enabling isolation technique for indium-mediated allylation reactions in water.

An efficient method was developed to allylate aldehydes using an aqueous indium-mediated allylation reaction with fluorous-tagged allyl halides, and to directly purify the products by fluorous solid phase extraction (F-SPE).

Calmodulin bound to stress fibers but not microtubules involves regulation of cell morphology and motility.

Calmodulin (CaM) is a major cytoplasmic calcium receptor that performs multiple functions including cell motility. To investigate the mechanism of the regulation of CaM on cell morphology and motility, first we checked the distribution of CaM in the living cells using GFP-CaM as an indicator. We found that GFP-CaM showed a fiber-like distribution pattern in the cytosol of living Potorous tridactylis kidney (PtK2) cells but not in living HeLa cells.

MAPK pathway mediates EGR-1-HSP70-dependent cigarette smoke-induced chemokine production.

Cigarette smoking, a major risk factor for chronic obstructive pulmonary disease, can cause airway inflammation, airway narrowing, and loss of elasticity, leading to chronic airflow limitation. In this report, we sought to define the signaling pathways activated by smoke and to identify molecules responsible for cigarette smoke-induced inflammation. We applied cigarette smoke water extract (CSE) to primary human lung fibroblasts and found that CSE significantly increased CXC chemokine IL-8 production.

Highly efficient three-component synthesis of beta-lactams from N-methylhydroxylamine, aldehydes, and phenylacetylene.

The three-component reaction of N-substituted hydroxylamines, aldehydes, and phenylacetylene catalyzed by CuCl/2,2'-bipyridine in the presence of NaOAc under neat conditions afforded the corresponding beta-lactams in good to excellent yields. Aromatic, heteroaromatic, and aliphatic aldehydes are tolerated in this reaction. The electronic effects of the aldehydes were studied for the reaction with N-methylhydroxylamine and N-benzylhydroxylamine.