The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a-e, the corresponding β-ketoenamines 2a-e were converted into different β-ketoenamides 3a-g by N-acylation with 2-pyridinecarboxylic acid derivatives. These β-ketoenamides were treated with a mixture of TMSOTf and Hünig's base to promote the cyclocondensation to 4-hydroxypyrid...

Unsymmetrically substituted allenes (1,2-dienes) are inherently chiral and can be prepared in optically pure form. Nonetheless, to date the allene framework has not been incorporated into ligands for asymmetric catalysis. Since allenes project functionality differently than either tetrahedral carbon or chiral biaryls, they may create complementary chiral environments. This study demonstrates th...

ABSTRACT New indenylidene-type second generation catalysts bearing modified unsymmetrically substituted N-heterocyclic carbene ligands were synthesized. The complexes contain an N-mesityl and N'-nitrobenzyl substituted NHC ligand. The precursors of free carbenes-imidazolinium salts-were obtained in an easy and environment-friendly way (under aqueous or neat conditions). The new catalysts were p...

Carpal tunnel syndrome is diagnosed by clinical symptoms, Tinel's sign, Phalen's test and electromyography. Carpal tunnel pressure measurement can also aid in the precise identification of excessive pressure sites that indicate locations for release. In this study, pressure measurements made during endoscopic carpal tunnel release at 5 points were significantly higher anywhere in the carpal tun...

A FOUNDATION FOR TUNNEL-COMPLEX PROTOCOLS Alwyn E. Goodloe Carl A. Gunter Tunnel-complex protocols construct different tunnel topologies by directing tunnelestablishment protocols to set up pair-wise tunnels between different nodes, where the resulting tunnel complex satisfies some security requirement such as negotiating a defense in depth. Such protocols ease the burden on network managers de...

Endoscopic carpal tunnel release is a controversial procedure used in the treatment of carpal tunnel syndrome. Although endoscopic carpal tunnel release is associated with less incisional pain and faster recovery time than the open carpal tunnel release, opponents of endoscopic carpal tunnel release suggest that its benefits are outweighed by its higher complication rates from median nerve tran...

The long and large-diameter uncharged hole-boring (LLB) method is a cut-blasting used to reduce vibration induced by blasting. This typically involves creating an hole with 382 mm diameter drilling 50 m in the tunnel excavation direction at time. reported provide relatively good reduction high blasting efficiency through short compared traditional cut methods. In this study, advanced LLB incorp...

qomroud water conveyance tunnel (lot 1&2) with the length of 16 kilometers is considered as one of the greatest development and national projects in iran. since about 2 kilometers of tunnel pass through alluvium and the rest of the tunnel pass through various types of geological units, and due to the complexity of geological condition and variety of effective criteria, suitable selection of...