Rethinking cross-coupling

Abstract

Up, up and away: Energy up-conversion, the generation of a high-energy excited state by absorption of two lowenergy photons, is an emerging technique with possible applications in different fields, such as harnessing red or infrared solar photons to power photovoltaic devices. COMMUNICATIONS . 9566 -9570Nickel-Catalyzed C À P Cross-Coupling by C À CN Bond Cleavage Prosperous coupling: A nickel-catalyzed CÀP cross-coupling reaction with Me 3 SiPPh 2 by carbon-cyano bond cleavage has been developed. This method is characterized by its simplicity and wide application to the synthesis of various monophosphorus and P,N bidentate ligands (see scheme). Unprotected synthesis: The first enantioselective chiral phosphoric acid catalyzed transfer hydrogenation of unprotected ortho-hydroxybenzophenone NÀH imines by using a Hantzsch ester as the hydrogen source afforded the corresponding chiral N,O-unprotected ortho-hydroxydiarylmethyl-A C H T U N G T R E N N U N G amines in high yields with excellent enantioselectivities (see scheme). Clearing the air! By using a balloon pressure of CO, the direct oxidative carbonylation of various heteroarenes with different alcohols was achieved in good to high yields with air as the oxidant in the presence of PdCl 2 A C H T U N G T R E N N U N G (PPh 3 ) 2 (see scheme). Notably, this transformation was carried out under base-free conditions. The reaction showed remarkably high regioselectivity and presents an environmentally benign protocol for the synthesis of carboxylic acid derivatives. Domino Reactions Continuous-Flow ChemistryH. E. Bartrum, D. C. Blakemore, C. J. Moody,* C. J. Hayes* . . -9589Rapid Access to a-Alkoxy and a-Amino Acid Derivatives through Safe Continuous-Flow Generation of Diazoesters Microreactors: A highly efficient continuous-flow process has been developed for the synthesis of diazoesters from arylsulfonylhydrazones by means of in-flow Bamford-Stevens reactions. Furthermore, a range of a-alkoxy and a-amino acid derivatives have been prepared in excellent yields through rhodium(II)-mediated O À H and N À H insertions, without the need to isolate or handle the potentially hazardous diazo species (see scheme). . 9590 -9594Multivalued Logic Gates Based on DNA Alternative concept of logic: The ensemble of DNA on the surface of silica nanoparticles could be used to design ternary logic gates, which go beyond common binary operations. Herein, by assigning more than two possible states to input and output signals, thereby implementing multivalued logic, the densities of information can be increased (see scheme). Go with the flow! A method for conversion of keto halides to lactams by means of sequential azidation and intramolecular Schmidt reaction in a combined flow format is described (see scheme; MWI = microwave irradiation, TFA = trifluoroacetic acid). Continuous-Flow Chemistry(Ln = La (1), Tb (2), saOH 2 = salicylaldoxime) were synthesized by a twostep self-assembly process from MnCl 2 , saOH 2 , and LnA C H T U N G T R E N N U N G (NO 3 ) 3 under basic conditions i...

Applications of Bond Energy‐Based Thermodynamic Analysis to the Feasibility of Unfunctionalized C−C Cross‐Coupling Reactions

“…Aggarwal group modified the classical Suzuki‐Miyaura reaction in 2014 to utilize the reactivity of aryl lithium to form aryl borates which undergo 1,2‐migration in the presence of oxidant (e. g., NBS) followed by elimination to give the C sp3 −C sp2 coupling [48] . The advantages and limitations of this FFCC type coupling have been reviewed earlier and thus are not repeated here [49] …”

“…[48] The advantages and limitations of this FFCC type coupling have been reviewed earlier and thus are not repeated here. [49] C sp3 À C sp bonds…”

On-Surface Heck Reaction of Aryl Bromides with Alkene on Au(111) with Palladium as Catalyst

“…Cross-coupling reactions in solution are extremely powerful tools for creating C–C single bonds and generating molecular diversity. They allow highly selective joining of organic moieties A and B into A–B while avoiding formation of A–A or B–B. Because most of the organic molecules contain consecutive C–C bonds, these reactions are tremendously useful in the synthesis of organic compounds, including pharmaceuticals and conjugated organic materials.…”