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Donor-functionalized silanes with stereogenic silicon centers are extremely rare. A convenient stereocontrolled route to a nitrogen-oxygen-functionalized silicon-chiral compound with an additional aminomethyl function is presented. This silane was directly achieved in stereochemically pure form by a simple nucleophilic substitution reaction. Owing to the unique asymmetry of this silane and the presence of three donor functions, the first monomeric butyllithium compound with lithium-centered chirality could be isolated; the configuration was assigned by X-ray crystallography. This [silane⋅ tBuLi] complex undergoes an unexpected deprotonation/stereospecific substitution sequence in toluene, leading to the development of a convenient one-pot synthesis of a functionalized silicon-chiral benzylsilane, which proceeds with inversion of configuration and complete preservation of the stereochemical integrity at silicon., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A facile synthesis of chiral cyclic alkyl aminocarbene-gold(I) complexes from gold-free 1,7-enyne substrates was developed. The novel cyclization-rearrangement reaction sequence is triggered by the addition of (Me2S)AuCl to different 1,7-enynes and leads to structurally unique carbene-gold(I) complexes in high yields. These novel complexes are catalytically active and inhibit the proliferation of different human cancer cell lines., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Catalytic, selective, and controlled oxidative functionalization of C-H bonds using molecular oxygen as an oxidant remains highly desirable and equally challenging in the development of synthetic methodologies. Presented herein is a one-pot oxygenase cascade reaction wherein a copper(I)-catalyzed oxygenase reaction transforms the allylic methyl group in 3-methylidene oxindoles into an aldehyde, which then undergoes an aldol-oxa-Michael addition sequence with β-ketoesters to yield dihydrofuran-bearing oxindoles., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A one-pot transformation of alkan-1-ols into 2-chloroalkan-1-ols is described. As a practical application, terpene-derived primary alcohols were converted into semiochemicals such as olfactory lactones (aerangis lactone, whisky lactone, and cognac lactone) and pheromones (cruentol and ferrugineol). Using heptane-1,7-diol as a bifunctional substrate, the corresponding bis-epoxide was synthesized by bidirectional synthesis in good yield and high enantioselectivity.

A route towards the synthesis of N,O-functionalized silicon-stereogenic organosilanes with excellent optical purities has been developed. Investigations into the stereoconvergence and configurational stability of an aminomethoxysilane suggest a kinetically controlled multistep substitution mechanism. Selective exchange of the Si-N bond by a second Si-O bond builds the basis for the controlled formation of chiral siloxane units with different oxygen-containing functional groups. Subsequent reactions of the chiral aminomethoxysilanes with hydroxy groups support a general inversion mechanism at the asymmetrically substituted silicon atom of N,O-functionalized organosilanes., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Dipolar cycloaddition: A highly efficient copper(I)-catalyzed enantioselective [3+2] cycloaddition reaction of 1,3-fused cyclic azomethine ylides and nitroalkenes has been developed. This method provides access to functionalized tropane scaffolds with several quaternary and tertiary stereocenters in a single step under mild reaction conditions., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cousins you can count on: An iridoid-inspired compound collection was synthesized efficiently by the resolution of cyclic enones in an asymmetric cycloaddition with azomethine ylides. The collection contained novel potent inhibitors of the Wnt and Hedgehog signaling pathways., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Four new beilschmiedic acid derivatives, cryptobeilic acids A-D (1-4), and tsangibeilin B (5) have been isolated from the bark of Beilschmiedia cryptocaryoides collected from Madagascar. Their structures were elucidated using detailed spectroscopic and spectrometric methods. Cryptobeilic acid A (1) and tsangibeilin B (5) structures were confirmed by single-crystal X-ray diffraction analysis. Compounds 1-5 displayed moderate antibacterial activity against Escherichia coli 6r3, Acinetobacter calcoaceticus DSM 586, and Pseudonamas stutzeri A1501, with the minimum inhibitory concentrations ranging from 10 to 50 μM, respectively. In addition, the compounds exhibited antiplasmodial activity against erythrocytic stages of chloroquine-resistant Plasmodium falciparum strain NF54 and weak cytotoxicity against L6 cell lines.

New atom-economical, environmental friendly, direct oxidative intermolecular processes of amination and hydrazination of nonprefunctionalized arenes were developed. The products were formed in a good regioselective manner under organocatalytic conditions at ambient temperature.

A straightforward substitution of silicon-bonded methoxy groups by a lithium amide leading to aminomethoxysilanes is presented. DFT calculations allow thermodynamic insight into the unusual equilibrium conditions. The applicability of N,O-functionalised organosilanes is exemplified by the convenient synthesis of an unsymmetrical methoxydisiloxane.

The title compound, C(22)H(24)OSi or Ph(3)SiO(t)Bu, shows a distorted tetra-hedral coordination sphere around the Si atom. The C-O-Si angle is 135.97 (12)° and the O-Si distance is 1.6244 (13) Å. The mol-ecules are held together by weak inter-actions only. An H⋯H distance of 2.2924 (7) Å is found between aryl H atoms and is the shortest inter-molecular distance in the structure. With regard to the broad applicability of R(3)SiO structural motifs in all fields of chemistry, the mol-ecule demonstrates a common model system for silicon centers surrounded by sterically demanding substituents.

Introduction: Increased rates of multidrug-resistant (MDR) tuberculosis (TB) has been reported from countries close to Denmark. We evaluated the incidence of drug resistance in Denmark in order to determine the magnitude of the problem., Materials and Methods: Susceptibility testing was performed in isolates from 85.4% of all notified patients during 1991-1998. Epidemiological information was retrieved from the mandatory notification forms., Results: Total drug resistance remained largely constant, although a minor increase was observed in 1997-1998. Monoresistance was observed in 7.3% of the isolates. Among 3.6% polyresistant isolates, resistance to isoniazid and streptomycin accounted for 2.8%, whereas MDR accounted for 0.5%. The MDR strains displayed different restriction fragment length polymorphism (RFLP) patterns, and no matches were identified in the international MDR database. Drug resistance in untreated Danes and foreigners were 5.9% and 14.6%, respectively. Among Danes and foreigners with previous TB, 6.2% and 22.7% had drug resistance, respectively. Increased drug resistance was found among untreated Danes aged 25-54 years mainly due to a single isoniazid- and streptomycin-resistant RFLP-cluster. Among all patients with isoniazid- and streptomycin-resistance, 77.0% had clustered strains., Discussion: In conclusion, although drug resistance among untreated Danes was close to the rate estimated in good national programmes, close monitoring is needed in future years, as active transmission of isoniazid- and streptomycin-resistant Mycobacterium tuberculosis was demonstrated.

The present study is based on notified cases of tuberculosis (TB) in the National tbc. register 1972-1996. A decline in Tb incidence was seen from 1972 and until the mid-1980's. Subsequently the trend has reversed due to an increasing number of TB cases in foreigners. In 1996, 60% of all cases of TB in Denmark were found in foreigners reflecting the rising number of refugees and their families arriving in Denmark from highly endemic areas, mainly Somalia. Among native Danes the TB incidence fell from 14 per 100,000 in 1972 to 4 per 100,000 in the 1980's and stabilized at this very low level. The unchanged incidence in Danes covers a falling incidence in the older and a rising incidence in the younger and middle-aged adult population, mainly in the capital. Approximately half of the cases occur in high-risk groups. The TB-epidemic is close to elimination in the indigenous Danish population, but the disease is maintained at a low level probably due to increased patient and doctor delay and resulting microepidemics primarily in high-risk populations.

DNA-fingerprinting or RFLP (Restriction Fragment Length Polymorphism) is a molecular biological technique which allows differentiation between tuberculosis strains. The technique is based on the occurrence of repetitive elements in the mycobacterial genome and is a powerful tool in epidemiological studies. DNA-fingerprinting is also of value in tracking the spread of infection in patients with tuberculosis. The latter is illustrated in two case stories.