Chiral Cu(salen)-Based Metal–Organic Framework for Heterogeneously Catalyzed Aziridination and Amination of Olefins

A homochiral 3D porous metal–organic framework was assembled from a chiral dicarboxylic acid-functionalized Cu­(salen)-based catalyst and could serve as an efficient heterogeneous catalyst for aziridination and allylic amination of olefins. Besides easy separation and reuse of the catalyst, the chiral framework confinement could impart substrate size selectivity, enhance catalyst activity, and induce product enantioselectivity

Chiral Cu(salen)-Based Metal–Organic Framework for Heterogeneously Catalyzed Aziridination and Amination of Olefins

A homochiral 3D porous metal–organic framework was assembled from a chiral dicarboxylic acid-functionalized Cu­(salen)-based catalyst and could serve as an efficient heterogeneous catalyst for aziridination and allylic amination of olefins. Besides easy separation and reuse of the catalyst, the chiral framework confinement could impart substrate size selectivity, enhance catalyst activity, and induce product enantioselectivity

Chiral 3D Covalent Organic Frameworks for High Performance Liquid Chromatographic Enantioseparation

In spite of their great promise for enantioselective processes due to the rich host–guest chemistry, it remains a challenge to construct covalent organic frameworks (COFs) with chiral three-dimensional (3D) structures. Here we report bottom-up synthesis of the first example of 3D chiral COFs by imine condensation of an enantiopure 2-fold symmetric TADDOL-derived tetraaldehyde with a tetrahedral tetra­(4-anilyl)­methane. After postsynthetic oxidation of imine linkages, the framework is transformed into an amide-linked COF with retention of crystallinity and permanent porosity as well as enhanced chemical stability. The resultant isostructural COFs feature a 4-fold interpenetrated diamondoid open framework with tubular channels decorated with chiral dihydroxy auxiliaries. Both COFs can be used as chiral stationary phases for high performance liquid chromatography to enantioseparate racemic alcohols, and the oxidized COF shows superior separation performance compared to the pristine framework

Image_2_A novel predictive model for new-onset atrial fibrillation in patients after isolated cardiac valve surgery.TIF

BackgroundPostoperative atrial fibrillation (POAF) is a severe complication after cardiac surgery and is associated with an increased risk of ischemic stroke and mortality. The main aim of this study was to identify the independent predictors associated with POAF after isolated valve operation and to develop a risk prediction model.MethodsThis retrospective observational study involved patients without previous AF who underwent isolated valve surgery from November 2018 to October 2021. Patients were stratified into two groups according to the development of new-onset POAF. Baseline characteristics and perioperative data were collected from the two groups of patients. Univariate and multivariate logistic regression analyses were applied to identify independent risk factors for the occurrence of POAF, and the results of the multivariate analysis were used to create a predictive nomogram.ResultsA total of 422 patients were included in the study, of which 163 (38.6%) developed POAF. The Multivariate logistic regression analysis indicated that cardiac function (odds ratio [OR] = 2.881, 95% confidence interval [CI] = 1.595–5.206; P ConclusionCardiac function, left atrial diameter index, operative time, neutrophil count, and fever were independent predictors of POAF in patients with isolated valve surgery. Establishing a nomogram model based on the above predictors helps predict the risk of POAF and may have potential clinical utility in preventive interventions.</p

Image_1_A novel predictive model for new-onset atrial fibrillation in patients after isolated cardiac valve surgery.TIF

BackgroundPostoperative atrial fibrillation (POAF) is a severe complication after cardiac surgery and is associated with an increased risk of ischemic stroke and mortality. The main aim of this study was to identify the independent predictors associated with POAF after isolated valve operation and to develop a risk prediction model.MethodsThis retrospective observational study involved patients without previous AF who underwent isolated valve surgery from November 2018 to October 2021. Patients were stratified into two groups according to the development of new-onset POAF. Baseline characteristics and perioperative data were collected from the two groups of patients. Univariate and multivariate logistic regression analyses were applied to identify independent risk factors for the occurrence of POAF, and the results of the multivariate analysis were used to create a predictive nomogram.ResultsA total of 422 patients were included in the study, of which 163 (38.6%) developed POAF. The Multivariate logistic regression analysis indicated that cardiac function (odds ratio [OR] = 2.881, 95% confidence interval [CI] = 1.595–5.206; P ConclusionCardiac function, left atrial diameter index, operative time, neutrophil count, and fever were independent predictors of POAF in patients with isolated valve surgery. Establishing a nomogram model based on the above predictors helps predict the risk of POAF and may have potential clinical utility in preventive interventions.</p

Chiral Memory in Dynamic Transformation from Porous Organic Cages to Covalent Organic Frameworks for Enantiorecognition Analysis

The preservation of chirality during a transformation process, known as the “chiral memory” effect, has garnered significant attention across multiple research disciplines. Here, we first report the retention of the original chiral structure during dynamic covalent chemistry (DCC)-induced structural transformation from porous organic cages into covalent organic frameworks (COFs). A total of six two-dimensional chiral COFs constructed by entirely achiral building blocks were obtained through the DCC-induced substitution of chiral linkers in a homochiral cage (CC3-R or -S) using achiral amine monomers. Homochirality of these COFs resulted from the construction of 3-fold-symmetric benzene-1,3,5-methanimine cores with a propeller-like configuration of one single-handedness throughout the cage-to-COF transformation. The obtained chiral COFs can be further utilized as fluorescence sensors or chiral stationary phases for gas chromatography with high enantioselectivity. The present study thus highlighted the great potential to expand the scope of functional chiral materials via DCC-induced crystal-to-crystal transformation with the chiral memory effect

Chiral Memory in Dynamic Transformation from Porous Organic Cages to Covalent Organic Frameworks for Enantiorecognition Analysis

The preservation of chirality during a transformation process, known as the “chiral memory” effect, has garnered significant attention across multiple research disciplines. Here, we first report the retention of the original chiral structure during dynamic covalent chemistry (DCC)-induced structural transformation from porous organic cages into covalent organic frameworks (COFs). A total of six two-dimensional chiral COFs constructed by entirely achiral building blocks were obtained through the DCC-induced substitution of chiral linkers in a homochiral cage (CC3-R or -S) using achiral amine monomers. Homochirality of these COFs resulted from the construction of 3-fold-symmetric benzene-1,3,5-methanimine cores with a propeller-like configuration of one single-handedness throughout the cage-to-COF transformation. The obtained chiral COFs can be further utilized as fluorescence sensors or chiral stationary phases for gas chromatography with high enantioselectivity. The present study thus highlighted the great potential to expand the scope of functional chiral materials via DCC-induced crystal-to-crystal transformation with the chiral memory effect

Chiral Memory in Dynamic Transformation from Porous Organic Cages to Covalent Organic Frameworks for Enantiorecognition Analysis

The preservation of chirality during a transformation process, known as the “chiral memory” effect, has garnered significant attention across multiple research disciplines. Here, we first report the retention of the original chiral structure during dynamic covalent chemistry (DCC)-induced structural transformation from porous organic cages into covalent organic frameworks (COFs). A total of six two-dimensional chiral COFs constructed by entirely achiral building blocks were obtained through the DCC-induced substitution of chiral linkers in a homochiral cage (CC3-R or -S) using achiral amine monomers. Homochirality of these COFs resulted from the construction of 3-fold-symmetric benzene-1,3,5-methanimine cores with a propeller-like configuration of one single-handedness throughout the cage-to-COF transformation. The obtained chiral COFs can be further utilized as fluorescence sensors or chiral stationary phases for gas chromatography with high enantioselectivity. The present study thus highlighted the great potential to expand the scope of functional chiral materials via DCC-induced crystal-to-crystal transformation with the chiral memory effect

Chiral Memory in Dynamic Transformation from Porous Organic Cages to Covalent Organic Frameworks for Enantiorecognition Analysis

The preservation of chirality during a transformation process, known as the “chiral memory” effect, has garnered significant attention across multiple research disciplines. Here, we first report the retention of the original chiral structure during dynamic covalent chemistry (DCC)-induced structural transformation from porous organic cages into covalent organic frameworks (COFs). A total of six two-dimensional chiral COFs constructed by entirely achiral building blocks were obtained through the DCC-induced substitution of chiral linkers in a homochiral cage (CC3-R or -S) using achiral amine monomers. Homochirality of these COFs resulted from the construction of 3-fold-symmetric benzene-1,3,5-methanimine cores with a propeller-like configuration of one single-handedness throughout the cage-to-COF transformation. The obtained chiral COFs can be further utilized as fluorescence sensors or chiral stationary phases for gas chromatography with high enantioselectivity. The present study thus highlighted the great potential to expand the scope of functional chiral materials via DCC-induced crystal-to-crystal transformation with the chiral memory effect

Chiral Memory in Dynamic Transformation from Porous Organic Cages to Covalent Organic Frameworks for Enantiorecognition Analysis

The preservation of chirality during a transformation process, known as the “chiral memory” effect, has garnered significant attention across multiple research disciplines. Here, we first report the retention of the original chiral structure during dynamic covalent chemistry (DCC)-induced structural transformation from porous organic cages into covalent organic frameworks (COFs). A total of six two-dimensional chiral COFs constructed by entirely achiral building blocks were obtained through the DCC-induced substitution of chiral linkers in a homochiral cage (CC3-R or -S) using achiral amine monomers. Homochirality of these COFs resulted from the construction of 3-fold-symmetric benzene-1,3,5-methanimine cores with a propeller-like configuration of one single-handedness throughout the cage-to-COF transformation. The obtained chiral COFs can be further utilized as fluorescence sensors or chiral stationary phases for gas chromatography with high enantioselectivity. The present study thus highlighted the great potential to expand the scope of functional chiral materials via DCC-induced crystal-to-crystal transformation with the chiral memory effect