[Research on Dry Chemical Detection TechnologyBased on Reflectance Photometry].

In response to the issues of insufficient stability and accuracy in dry chemical detection using reflectance photometry, caused by the divergence and multiple internal reflections of the reflected light signal from the sample and the multilayer dry film test strip, a dry chemical reflectance photometry detection system based on an integrating sphere is designed. Firstly, an integrating sphere device is incorporated to reduce signal divergence and loss, ensuring even detection of the sample's reflected light signal and improving detection stability. Secondly, Light Tools optical simulation analysis is performed, and an integrating sphere detection model is established. Thirdly, the Williams-Clapper equation is employed to correct the error in reflectance density caused by multiple internal reflections, enhancing detection accuracy. Experimental validation demonstrates that the developed integrating sphere-based dry chemical reflectance photometry detection system improves the stability and accuracy of the detection system.

Constructing the Architecturally Distinctive ABD-Tricycle of Phomactin A through an Intramolecular Oxa-[3 + 3] Annulation Strategy.

Our efforts in constructing the ABD-ring of phomactin A through an intramolecular oxa-[3 + 3] annulation strategy is described. This struggle entailed finding a practical and efficient preparation of annulation precursor, and a realization of the unexpected competing regioisomeric pathway. The success entailed accessing the A-ring through Diels-Alder cycloaddition of Rawal's diene. Furthermore, the discovery that the regioisomers from the annulation existed as atropisomers with respect to the D-ring olefin and that they could be equilibrated to the desired ABD-tricycle, allowing large quantities of tricycle to be accessed.

An Enantioselective Synthesis of the ABD Tricycle for (-)-Phomactin A Featuring Rawal's Asymmetric Diels-Alder Cycloaddition.

An enantioselective synthesis of the ABD-ring of (-)-phomactin A is described here. The sequence features Rawal's asymmetric Diels-Alder cycloaddition. The overall length is significantly reduced from our previous attempt.

An Enantioselective Synthesis of the ABD Tricycle for (-)-Phomactin A Featuring Rawal's Asymmetric Diels-Alder Cycloaddition.

An enantioselective synthesis of the ABD-ring of (-)-phomactin A is described here. The sequence features Rawal's asymmetric Diels-Alder cycloaddition. The overall length is significantly reduced from our previous attempt.

Tandem azidination- and hydroazidination-Huisgen [3 + 2] cycloadditions of ynamides. Synthesis of chiral amide-substituted triazoles.

Tandem azidination- and hydroazidination-Huisgen [3 + 2] cycloadditions of ynamides are described here. These processes are regioselective and chemoselective, leading to the synthesis of chiral amide-substituted triazoles.

A rhodium(I)-catalyzed formal allenic Alder ene reaction for the rapid and stereoselective assembly of cross-conjugated trienes.

A rhodium(I)-catalyzed allenic Alder ene reaction to prepare cross-conjugated trienes has been discovered. The scope and limitations are currently being investigated, and the results obtained to date are reported on. This method shows enticing functional group compatibility by tolerating terminal and internal alkynes, hydroxyl, sulfonamide, ether, and diester groups. Progress has been made to increase the stereoselectivity of the olefinic side chain via an unprecendented iridium(I) catalyzed Alder-ene reaction.