Total syntheses of the parvistemoline alkaloids enabled by stereocontrolled Ir/Pd-catalyzed allylic alkylation.

The functionalized polycycle with densely contiguous tertiary stereocenters is a formidable challenge in synthesizing the parvistemoline family of Stemona alkaloids. We herein report their catalytic, asymmetric total syntheses in 13-14 steps from commercially available 2-(methoxycarbonyl)-pyrrole, featuring the development and deployment of an Ir/Pd-synergistically-catalyzed allylation of α-non-substituted keto esters with secondary aryl-substituted alcohols, stereodivergently accessible to four stereoisomers. Using chiral Pd-enolate and Ir π-allyl complex under neutral conditions, no epimerization occurs.

Total Syntheses of Cinchona Alkaloids via Photoredox-Catalyzed Deoxygenative Arylation.

Metallaphotoredox-enabled deoxygenative arylation of alcohols is a recently developed robust synthetic strategy for sp-sp coupling by MacMillan. Inspired by this method, we report herein its first utilization in natural product total synthesis through realizing the coupling of 4-bromo-quinoline or 4-bromo-6-methoxyquinoline with quincorine or quincoridine, respectively. The alcohols were de novo synthesized in racemic form by a key step of the intramolecular Diels-Alder reaction or in an enantioselective manner by Ir/amine dual-catalyzed allylation.

[Double-column Die-punch fractures of distal radius treated with butterfly plate fixation via Henry approach].

Objective: To explore clinical effect of open reduction and internal fixation with Henry's approach butterfly plate in treating double-column Die-punch fractures of distal radius.

Methods: From January 2018 to June 2021, 26 patients with double-column Die-column distal radius were treated with open reduction and internal fixation through Henry's surgical approach and using distal radius volar column plate(butterfly plate), including 14 males and 12 females, aged from 20 to 75 years old with an average age of (44.2±3.

Cathodized copper porphyrin metal-organic framework nanosheets for selective formate and acetate production from CO electroreduction.

An efficient and selective Cu catalyst for CO electroreduction is highly desirable since current catalysts suffer from poor selectivity towards a series of products, such as alkenes, alcohols, and carboxylic acids. Here, we used copper(ii) paddle wheel cluster-based porphyrinic metal-organic framework (MOF) nanosheets for electrocatalytic CO reduction and compared them with CuO, CuO, Cu, a porphyrin-Cu(ii) complex and a CuO/complex composite. Among them, the cathodized Cu-MOF nanosheets exhibit significant activity for formate production with a faradaic efficiency (FE) of 68.