Iodine-catalyzed guanylation of amines with N,N'-di-Boc-thiourea.

Herein, we report that iodine-catalyzed guanylation of primary amines can be accomplished with N,N'-di-Boc-thiourea and TBHP to afford the corresponding guanidines in 40-99% yields. Oxidation of the HI byproduct by TBHP eliminates the need for an extra base to prevent the protonation of substrates and makes the reaction especially useful for both electronically and sterically deactivated primary anilines.

Development of a fast-responsive and turn on fluorescent probe with large Stokes shift for specific detection of cysteine in vivo.

Cysteine has a great effect on the physiological and pathological processes, which could bring out various diseases such as skin lesions, edema, hair depigmentation, Alzheimer's, Parkinson's, and liver damage due to the abnormal concentrations of cysteine. Therefore, it is of great impoatance to develop a method for imaging Cys. Herein, a novel fluorescent probe was developed for imaging Cys in vivo specially.

A highly diastereoselective decarboxylative mannich reaction of β-keto acids with optically active N-sulfinyl α-imino esters.

A range of protected γ-oxo-α-amino esters have been prepared in a highly regio- and stereoselective manner through the decarboxylative Mannich reaction of β-keto acids with optically active N-tert-butanesulfinyl α-imino esters in the presence of 3 mol % La(OTf)(3) or 5 mol % Y(OTf)(3) at 20 °C. Preliminary mechanistic studies indicate that the reaction proceeds through imine addition followed by decarboxylation.

Catalytic decarboxylative alkylation of β-keto acids with sulfonamides via the cleavage of carbon-nitrogen and carbon-carbon bonds.

An efficient decarboxylative alkylation reaction of β-keto acids with N-benzylic or N-allylic sulfonamides has been developed, for the first time, through sequential cleavage of carbon-nitrogen and carbon-carbon bonds in the presence of 10 mol% of FeCl(3).

Phylogenetic analysis of methanogens in the pig feces.

In order to assess methanogen diversity in feces of pigs, archaeal 16S rRNA gene clone libraries were constructed from feces of the pig. After the amplification by PCR using primers Met86F and Met1340R, equal quantities of PCR products from each of the five pigs were mixed together and used to construct the library. Sequence analysis showed that the 74 clones were divided into ten phylotypes as defined by RFLP analysis.

Catalyst-free alkylation of sulfinic acids with sulfonamides via sp(3) C-N bond cleavage at room temperature.

An unprecedented catalyst-free alkylation of sulfinic acids with sulfonamides has been developed via sp(3) C-N bond cleavage at room temperature. In the absence of external catalysts and additives, a wide variety of N-benzylic and N-allylic sulfonamides couple with sulfinic acids to give structurally diversified sulfones in moderate to excellent yields. Furthermore, the reaction of N-(2-acyl)allylic sulfonamides with sulfinic acids provides a convenient access to trisubstituted allyl sulfones with exclusive Z selectivity.

Selective benzylic and allylic alkylation of protic nucleophiles with sulfonamides through double Lewis acid catalyzed cleavage of sp3 carbon-nitrogen bonds.

The acid-catalyzed benzylic and allylic alkylation of protic nucleophiles is fundamentally important for the formation of carbon-carbon and carbon-heteroatom bonds, and it is a formidable challenge for benzylic and allylic amine derivatives to be used as the alkylating agents. Herein we report a highly efficient benzylic and allylic alkylation of protic carbon and sulfur nucleophiles with sulfonamides through double Lewis acid catalyzed cleavage of sp(3) carbon-nitrogen bonds at room temperature. In the presence of a catalytic amount of inexpensive ZnCl(2)-TMSCl (TMSCl: chlorotrimethylsilane), 1,3-diketones, beta-keto esters, beta-keto amides, malononitrile, aromatic compounds, thiols, and thioacetic acid can couple with a broad range of tosyl-activated benzylic and allylic amines to give diversely functionalized products in good to excellent yields and with high regioselectivity.

Catalytic selective bis-arylation of imines with anisole, phenol, thioanisole and analogues.

The first highly efficient double Friedel-Crafts reaction of N-tosyl imines with anisole, phenol, thioanisole and analogues has been developed to produce the corresponding symmetric diarylmethanes and triarylmethanes with high regioselectivity in the presence of a catalytic amount of Bi(2)(SO(4))(3)-TMSCl at room temperature.