Enantioselective Synthesis of Isoindolinone by Palladium-Catalyzed Aminoalkynylation of O-Phenyl Hydroxamic Ethers with Alkynes.

A highly efficient palladium-catalyzed asymmetric tandem aza-Heck/Sonogashira coupling reaction of O-phenyl hydroxamic ethers with terminal alkynes is described. This protocol enables versatile access to challenging chiral isoindolinone derivatives bearing a quaternary stereogenic center. The palladium-catalyzed aminoalkynylation reaction shows broad functional group tolerance and allows the straightforward preparation of isoindolinones with high efficiency and excellent enantioselectivity under mild conditions. DFT calculations were performed to disclose the reaction mechanism and the origins of the enantioselectivity.

Synthesis of Bis-Heterocycles Bearing Methyleneindole Motifs by Pd-Catalyzed Domino Reaction.

A highly robust, general, and practically simple palladium-catalyzed domino bicyclization strategy is presented to synthesize nitrogen-containing bis-heterocycles bearing methylene indole motifs from alkyne-tethered carbamoyl chlorides and ß,γ- or γ,δ-unsaturated hydrazones. The salient features of this transformation include broad substrate scope, good functional group tolerance, ease for scale-up, and convenient conversion.

Enantioselective Synthesis of Dihydropyrazoles by Palladium/Xu-Phos-Catalyzed Alleneamination of ß,γ-Unsaturated Hydrazones with Propargylic Acetates.

The palladium-catalyzed asymmetric carboamination reaction is one of the most significant transformations in organic chemistry. Herein, we report the first palladium-catalyzed asymmetric alleneamination of ß,γ-unsaturated hydrazones with propargylic acetates. This protocol enables the efficient installation of various multisubstituted allene groups onto dihydropyrazoles in good yields with excellent enantioselectivities. The chiral sulfinamide phosphine ligand Xu-5 exhibits highly efficient stereoselective control in this protocol. The salient features of this reaction include the readily available starting materials, a broad substrate scope, an easy scale-up, mild reaction conditions and versatile transformations.

Synthesis of Heterobenzyl Sulfoxides Enabled by Palladium-Catalyzed Allylic Alkylation of Sulfenate Anions with Allenamides.

A highly efficient palladium-catalyzed allenamide allylic alkylation of sulfenate anions under mild conditions is demonstrated. The present methodology provides a practical protocol to access various sulfoxide-containing heterocyclic compounds. The salient features of this transformation include a broad substrate scope, good functional group tolerance, easy to scale-up, and ready synthetic transformation.

High-resolution real-time 360° 3D model reconstruction of a handheld object with fringe projection profilometry.

The digitization of the complete shape of real objects has essential applications in fields of intelligent manufacturing, industrial detection, and reverse modeling. In order to build the full geometric models of rigid objects, the object must be moved relative to the measurement system (or the scanner must be moved relative to the object) to obtain and integrate views of the object from all sides, which not only complicates the system configuration but makes the whole process time-consuming. In this Letter, we present a high-resolution real-time 360° three-dimensional (3D) model reconstruction method that allows one to rotate an object manually and see a continuously updated 3D model during the scanning process. A multi-view fringe projection profilometry system acquires high-precision depth information about a handheld object from different perspectives and, meanwhile, the multiple views are aligned and merged together in real time. Our system employs stereo phase unwrapping and an adaptive depth constraint that can unwrap the phase of dense fringe images robustly without increasing the number of captured patterns. We then develop an efficient coarse-to-fine registration strategy to match the 3D surface segments rapidly. Our experiments demonstrate that our method can reconstruct the high-precision complete 3D model of complex objects under arbitrary rotation without any instrument assist and expensive pre/post-processing.

Synthesis of Multisubstituted Allenes by Palladium-Catalyzed Carboetherification of ß,γ-Unsaturated Ketoximes with Propargylic Acetates.

A highly efficient Pd-catalyzed carboetherification reaction of ß,γ-unsaturated ketoximes with propargylic acetates is demonstrated. This method provides a practical protocol for accessing the incorporation of an allene moiety into 3,5-disubstituted and 3,5,5-trisubstituted isoxazolines. The salient features of this transformation include a broad substrate scope, good functional group tolerance, an easy scale-up, versatile transformations, and applications in the late-stage modification of drugs.