Dedicated to Professor Xiyan Lu on the occasion of his 80th birthdayTransition-metal-catalyzed aryl C sp2 ÀN bond formation has been intensively studied over the past decade because of the importance of the amines and their derivatives in chemistry related fields.[1-9] The Pd-or Cu-catalyzed formation of anilines from electrophilic aryl halides and nucleophilic primary or secondary amines, pioneered by Buchwald and co-workers and Louie and Hartwig, as well as others, [10][11][12][13][14] is a hallmark reaction in this field. In 1998, Chan et al., Evans et al., and Lam et al. independently developed Cu-mediated oxidative amination of nucleophilic arylboronic acids with amines or other nucleophiles, [16][17][18][19][20] and the methods were later improved to include catalytic versions. [15,17,21,22] However, electrophilic amination of organometallic reagents by R 1 R 2 N + synthons, [23][24][25][26][27][28][29][30][31] though conceptually feasible, has received much less attention. [32][33][34][35][36][37] The putative catalytic cycle of this transformation is illustrated in Scheme 1: (1) reaction of R 1 R 2 N À X (as an electrophile) with the metal catalyst (M 1 ) would introduce the amine group to the metal center to form R 1 R 2 N-M 1 -X; [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] (2) transmetalation of RM 2 (M 2 = B(OH) 2 ) with R 1 R 2 N-M 1 -X to furnish R 1 R 2 N-M 1 R; and (3) final reductive elimination to form the CÀN bond.The groups of Liebeskind and Johnson have studied this type of CÀN bond formation employing NÀO derivatives. [32][33][34][35][36][37] N-Chloroamides, though attractive because of the ease of preparation [49][50][51] and the high activities of the N À Cl bond, [23,50,51] have seldom been utilized in catalytic electrophilic amination reactions. To the best of our knowledge, Göttlich et al. has primarily studied the Cu-mediated reaction of N-chloroamines with alkenes. [38,39,52] Herein, we communicate our results regarding ligandless copper-catalyzed electrophilic amination of arylboronic acids by N-chloroamides under mild conditions.Our initial experiments of N-chloro-N-phenylacetamide [49] (1 a) and phenylboronic acid (2 a) were carried out by using palladium catalysts. In all attempts, biphenyl was formed instead of the desired N-arylation product (3 a).

Abstract:The housing market in Chinese metropolises have become inflated significantly over the last decade. In addition to an economic upturn and housing policies that have potentially fueled the real estate bubble, factors that have contributed to the spatial heterogeneity of housing prices can be dictated by the amenity value in the proximity of communities, such as accessibility to business centers and transportation hubs. In the past, scholars have employed the hedonic pricing model to quantify the amenity value in relation to structural, locational, and environmental variables. These studies, however, are limited by two methodological obstacles that are relatively difficult to overcome. The first pertains to difficulty of data collection in regions where geospatial datasets are strictly controlled and limited. The second refers to the spatial autocorrelation effect inherent in the hedonic analysis. Using Beijing, China as a case study, we addressed these two issues by (1) collecting residential housing and urban amenity data in terms of Points of Interest (POIs) through web-crawling on open access platforms; and (2) eliminating the spatial autocorrelation effect using the Eigenvector Spatial Filtering (ESF) method. The results showed that the effects of nearby amenities on housing prices are mixed. In other words, while proximity to certain amenities, such as convenient parking, was positively correlated with housing prices, other amenity variables, such as supermarkets, showed negative correlations. This mixed finding is further discussed in relation to community planning strategies in Beijing. This paper provides an example of employing open access datasets to analyze the determinants of housing prices. Results derived from the model can offer insights into the reasons for housing segmentation in Chinese cities, eventually helping to formulate effective urban planning strategies and equitable housing policies.

The catalyzed semihydrogenation of dibromomethane (CH 2 Br 2 ) to methyl bromide (CH 3 Br) is a key step in the bromine-mediated upgradation of methane. This study presents a cutting-edge strategy combining density functional theory (DFT), catalytic tests complemented with the extensive characterization of a wide range of metal catalysts (Fe, Co, Ni, Cu, Ru, Rh, Ag, Ir, and Pt), and statistical tools for a computer-assisted investigation of this reaction. The steady-state catalytic tests identified four classes of materials comprising (i) poorly active (<8%) Fe/SiO 2 , Co/SiO 2 , Cu/SiO 2 , and Ag/SiO 2 ; (ii) Rh/SiO 2 and Ni/SiO 2 , which exhibit intermediate CH 3 Br selectivity (<60%); (iii) Ir/SiO 2 and Pt/SiO 2 , which display great propensity to CH 4 (>50%); and (iv) Ru/SiO 2 , which exhibits the highest selectivity to CH 3 Br (up to 96%). In-depth characterization of representative catalysts in fresh and used forms was done by X-ray diffraction, inductively coupled plasma optical emission spectroscopy, N 2 sorption, temperature-programmed reduction, Raman spectroscopy, electron microscopy, and X-ray photoelectron spectroscopy. The dimensionality reduction performed on the 272 DFT intermediate adsorption energies using principal component analysis identified two descriptors that, when employed together with the experimental data in a random forest regressor, enabled the understanding of activity and selectivity trends by connecting them to the energy intervals of the descriptors. In addition, a representative analytic model was found using the Bayesian inference. These findings illustrate the exciting opportunities presented by integrated experimental/computational screening and set the fundamental basis for the accelerated discovery of superior hydrodebromination catalysts and beyond.

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A general and efficient phosphorous acid-catalyzed cyclocondensation of β-ketoesters with o-aminobenzamides via selective C-C bond cleavage leading to quinazolinones is developed. This reaction proceeds smoothly under metal- and oxidant-free conditions, giving both 2-alkyl- and 2-aryl-substituted quinazolinones in excellent yields. This strategy can also be applied to the synthesis of other N-heterocycles, such as benzimidazoles and benzothiazoles.