We demonstrate the catalytic intermolecular [2 + 2] cycloaddition of electron-rich alkynes and a trifluoroiminopyruvate, affording the corresponding CF 3 -substituted isolable 2-azetines. Whereas [4 + 2] interaction affording acyclic imidates was predominant in the absence of a Lewis acid catalyst, using a catalytic amount of titanium(IV) tetrachloride was quite effective in promoting the desired [2 + 2] cycloaddition providing 2-azetines. Electron-rich arylsubstituted inner alkynes provided complete regioselectivity, and using a silyl group was effective for inducing the dominant [2 + 2] cycloaddition pathway. Both [2 + 2] cycloaddition and formation of γ-butenolides via a "5-exo-dig type" cyclization pathway were confirmed. Hydride reduction of a 2-azetine provided the azetine-substituted primary alcohol, and treatment with potassium t-butoxide promoted ring expansion, affording the 6-membered cyclic sulfonamide.
The Nakanoshima Challenge is a contest for developing sophisticated navigation systems of robots for collecting garbage in outdoor public spaces. In this study, a robot named Navit(oo)n is designed, and its performance in public spaces such as city parks is evaluated. Navit(oo)n contains two 2D LiDAR scanners with uniaxial gimbal mechanism, improving self-localization robustness on a slope. The gimbal mechanism adjusts the angle of the LiDAR scanner, preventing erroneous ground detection. We evaluate the navigation performance of Navit(oo)n in the Nakanoshima and its Extra Challenges.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.