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The development of chiral architectures for chiral ligand and catalyst discovery is essential for asymmetric catalysis. Herein, we report the concise synthesis of a Si-centered spirocyclic skeleton, spirobiphenoxasilin-diol (SPOSiOL), and its derived chiral ligands. Using the chemical resolution method, the optical SPOSiOL could be obtained in high yield on a gram scale. Preliminary studies indicated that this ligand scaffold has great potential in transition metal-catalyzed asymmetric reactions. This finding further highlights that the Si-centered spirocyclic scaffolds are of great value in asymmetric catalysis. [ABSTRACT FROM AUTHOR]

Reported here is the discovery of a redox‐neutral NiII/NiII catalytic cycle which is capable of the linear‐selective hydroarylation of unactivated alkenes with arylboronic acids for the first time. This novel catalytic cycle, enabled by the use of an electron‐rich diimine ligand, features broad substrate scope, and excellent functional‐group and heterocycle compatibility under mild reaction conditions in the absence of additional oxidants and reductants. Mechanistic investigations using kinetic analysis and deuterium‐labelling experiments revealed the protonation to be the rate‐determining step in this redox‐neutral catalysis, and the reversible chain‐walking nature of the newly developed diimine‐Ni catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic membranes assembled by immobilizing Pd nanocatalysts via immersion precipitation. • The high spatial distribution of Pd nanocatalysts enables high utilization of catalytic sites. • Catalytic nanoparticles act as hydride carriers transferring H* from sodium borohydride to 4-NP. • Pd nanocatalysts show low leaching within CMMRs due strong chemical interaction with polydopamine. • CMMRs combine UF separation (>90% rejection of 1 MDa PEO) with catalysis (>99% conversion of 4-NP). Catalytic membrane microreactors (CMMRs) are an exciting new technology that combine catalysis with membranes by seeding the high internal surface area of membranes with catalysts. This enables the continuous purification and production of organic compounds with high catalytic activity, while maintaining nanocatalyst size and stability. This study reports a simple two-step batch reaction approach for synthesizing stable Pd-immobilized catalytic membranes to transform 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in a flow-through CMMR system. The product (4-AP) is an essential intermediate for the polymer and solvent chemical industry. Pd-immobilized membranes exhibited strong catalytic activity for 4-NP reduction in the presence of NaBH 4 , with 4-fold higher reduction (79.7%) and 2-fold higher reduction rate (1.08 mol m−2h−1) as compared to control membranes without catalysts. The catalytic mechanisms were elucidated, such that the catalytic reduction processes were conducted via a sequential hydrogenation reaction where Pd nanocatalysts facilitated H* transfer from BH 4 - to 4-NP. Ultimately, the 4-AP product was gradually desorbed from the catalytic sites, achieving continuous reduction with high reduction efficiency. Furthermore, by combing ultrafiltration and catalysis, Pd-immobilized membranes showed >99% of 4-NP conversion and >90% of 1 MDa PEO rejection, demonstrating a great potential to be applied in high-efficient wastewater treatment processes. [ABSTRACT FROM AUTHOR]

A general synthetic protocol for the synthesis of simple phosphino-amine (PN) ligands is described with 19 ligands being isolated in good yields. High-throughput ligand screening uncovered the success of two of these ligands for aromatic amine alkylations via ruthenium-catalyzed hydrogen borrowing reactions. The combination of N,N'-bis(diphenylphosphino)- N,N'-dimethylpropylenediamine with a ruthenium(II) source and potassium hydroxide (15 mol%) is the optimal system for selective monobenzylations of aromatic amines (method A). Over 70% isolated yields have been achieved for the formation of 14 secondary aromatic amines under mild reaction conditions (120 8C and 1.05 equivalents of benzyl alcohol). On the other hand, N,N-bis(diphenylphosphino)- isopropylamine was the ligand utilized for both selective monomethylation and monoethylation reactions of aromatic amines (method B). Here the alcohol is charged as both the reaction medium and substrate and 9 examples are disclosed with all isolated yields exceeding 70%. These methods have been applied to the synthesis of important synthetic building blocks based on aminoferrocene. [ABSTRACT FROM AUTHOR]

Abstract: An efficient and simple process for the fixation of carbon dioxide (CO2) to aziridine for the synthesis of 2-oxazolidinone by using DBN as catalyst, LiI as an additive under atmospheric pressure was developed. This chemical fixation of CO2 could also be carried out at room temperature with prolonged reaction time. [Copyright &y& Elsevier]

A series of simple phosphino-amine ligands is synthesized and screened in aromatic amine alkylations via ruthenium-catalyzed hydrogen borrowing reactions. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "One-Pot Synthesis of 1-(Trifluoromethyl)-4-fluoro-1,2-dihydroisoquinolines and 4,4-Difluoro-1,2,3,4-tetrahydroisoquinolines" by Q. Liu and others, published in the periodical "Organic Letters" in 2013.

In comparison to related reactions under aerobic conditions, the utilization of Ph-I(OAc)2 changes the aminopalladation step from a cis-selective process to a trans-selective one. [ABSTRACT FROM AUTHOR]