Themed collection Celebrating the 80th Birthday of Professor Ei-ichi Negishi

Photo credit © Steve Scherer, Purdue University.

Recent developments in the sequential synthetic strategies including ruthenium-catalyzed silylative coupling followed by desilylation, leading to π-conjugated organic derivatives are presented.

Negishi coupling is an efficient and versatile tool for selective C–C bond formation in the synthesis of organic electronic, optical, electrochemical, and magnetic materials.

Axially chiral allenes are an important class of molecules widely existing in nature and also valuable chiral building blocks for organic synthesis. With more and more new protocols for racemic allenes and new chiral ligands being developed, a wide variety of novel and challenging transformations have been recently unveiled for the synthesis of this type of highly versatile compounds. In this review, we present a critical account of the enantioselective synthesis of axially chiral allenes.

Metal-mediated organic reactions have become one of the great frontiers of organic synthesis.

A stable pillar[5]arene-based pseudo[1]rotaxane P1′ was synthesized by the click reaction, which exhibited a dynamic slow disassembly process upon adding a strong-polar solvent or competitive guest. Moreover, this dynamic behavior might be used as a switch to turn on or off the bioactivity of the biotin moiety in aqueous solution.

A new synthetic route towards multisubstituted olefins was developed based on the direct cross coupling of alkenyl aluminium reagents, prepared by hydro- and carboalumination, with alkyl halides in the presence of an iron catalyst.

A highly diastereoselective Rh-catalyzed boronic acid addition to enantiopure sulfinylimines at room temperature providing γ-aryl GABA derivatives has been described.

This manuscript details a nickel-catalyzed method for the arylation of azole C–H bonds using perfluoro- and 2-nitro benzoates.

A gold catalyzed reaction for the preparation of morpholine and piperazine derivatives from alkynylalcohols or alkynylamines was developed.

Stable five-membered sulfur-containing metallacyclic allenes, 1-thia-2-metallacyclopenta-3,4-diene, were synthesized from the reactions of low-valent zirconocene or titanocene with alkynylthioamides.

A kinetic study on the intramolecular direct radical substitution reaction on tin atoms was undertaken.

A series of phthalic anhydrides underwent a 1,3-dipolar cycloaddition reaction with N-benzylazomethine ylide to produce unstable spiro(isobenzofuran-1,5′-oxazolidin)-3-ones, which underwent a subsequent reductive ring-opening reaction to afford 1(3H)-isobenzofuranones.

An unprecedented atropo-diastereoselective aryl–aryl coupling via arynes allows for the modular synthesis of enantiopure P,S-ligands.

ortho-C–H borylation of benzylic amines has been used in conjunction with a Suzuki–Miyaura coupling reaction to access biphenylbenzylic amines in good yields and requiring a single purification step.

Cu-catalysed cross-coupling for mono- and di-arylations of aryl and heteroaryl iodides and bromides is achieved with arylboronate esters.

ZrO₂ supported palladium catalysts promoted the aerobic oxidation of cyclohexanones to give phenols and aryl ethers.

We developed a simple and convenient method to assemble biaryls exploiting a photoredox catalyst and visible light.

2,6-Di(hetero)aryl substituted dithienothiazines with fine-tunable electronic properties are efficiently accessible by lithiation–lithium–zinc exchange–Negishi cross-coupling in a one-pot fashion.

The mechanistic study of the initial step in direct arylation provides valuable insight for optimising reaction conditions.

A high yielding and completely stereoselective hydrosilylation–Hiyama protocol has been established for the synthesis of highly functionalised E,E-dienes.

Unreported α-hydroxy-β-azido tetrazoles are prepared in a single step and mild conditions from readily available epoxy nitriles.

A series of 3,10-dialkylated picenes has been synthesized through sequential Ni-catalyzed alkynylation of a C–O bond, alkylation, and hydrogenation.

Polyhydroxylated piperidines are a functionally rich class of biologically active molecules that have broad therapeutic potential.

Convenient preparation of bisarylethyne–peptide conjugates, and a mild procedure for the H- or D-reduction of the bisarylethyne triple bond.

A facile and efficient iodine-promoted Meyer–Schuster rearrangement of propargyl alcohols for the synthesis of α-iodo-α,β-unsaturated ketones is presented.

A consecutive series of metal-catalyzed reactions for the preparation of enantiomerically pure piperidine derivatives.

The nickel catalyzed functionalization of C_Ar–SMe and C_sp³–SMe bonds by direct exchange of the sulfur atom with an activated sp³-carbon has been developed. The protocol allows the conversion of aryl and benzyl methyl sulfides to trimethylsilylated products in good yields.

Controlling the selectivity of an intramolecular Diels–Alder cycloaddition (IMDA) allows efficient synthetic access to the decalin motif of spirotetronates.

A highly efficient palladium-catalyzed asymmetric arylation of cyclic ketimine esters is developed, which provides the desired product in up to 99% yield with up to 99% ee. The mechanism of enantioselection is studied using DFT calculation.

A novel strategy to 4(3H)-quinazolinones from ketoalkynes and o-aminobenzamides through C–C triple bond fragmentation and two C–N bond formations under external oxidant and metal free conditions.

Asymmetric synthesis of (αS)-polyfluoroalkylated prolinols by the asymmetric Meerwein–Ponndorf–Verley-type reduction of perfluoroalkyl N-Boc-pyrrolidyl ketones with Et₂Zn has been developed.

The reaction of 2-arylmethyl-, 2-aryl-, and 2-alkyl substituted pyridine N-oxides with acrylates proceeded in the presence of a cationic Ir-rac-BINAP catalyst under heating conditions.

The allylic substitution for construction of quaternary carbons is used for synthesis of (−)-mesembrine.

Highly enantioselective phase-transfer-catalyzed epoxide-opening reaction and isomerization of cyclopentanones were achieved.

The challenging direct monoalkylation of primary and secondary amines with small triflates (C₁ to C₃) was accomplished in a flow microreactor by virtue of efficient mixing and short reaction times.

We report the first example of CO-enabled rhenium hydride complex-catalyzed inter- and intra-molecular hydroarylation of activated alkenes, with a broad reaction scope.

Ph₂P(O)-ethynylphenyl bromide showed higher reactivity in Sonogashira couplings than phenylethynylphenyl bromide because of the electron-withdrawing nature of the Ph₂P(O) group.

4-Alkenyl-5H-1,2,3-oxathiazole 2,2-dioxides undergo Michael/Michael cascade reaction with enals through iminium/enamine activation.

Regioselective H/D exchange reaction of functional groups on heterocycles proceeded via a transition metal-free reductive cyclization of sulfanyl 1,6-diynes using sodium borodeuteride/ethanol-D₁.

A new class of D–π-A organic dyes based on thieno[2,3,a]carbazole as an electron donor showed high efficiencies for dye-sensitized solar cells.

Ru-catalyzed dehydrogenative amide synthesis from aldehydes and amines was achieved, based on the idea of using a hemiaminal intermediate to generate the active Ru-hydride species.

Catalytic amounts of the base catalyst DABCO in cooperation with a proton source afford the [4 + 2] cycloadducts of isatins with but-3-yn-2-one in moderate to good yields. Moreover, related plausible mechanisms have been proposed in detail based on control and deuterium labeling experiments.

N-2-Aryl chelated 1,2,3-triazole-Ir(III) complexes with various substituents were prepared for the first time.

Selective, partial, or tandem reductions of bifunctional organic halides is reported.

A cationic Pd(II)-catalyzed intramolecular alkyne-carbonyl reductive coupling reaction of N-tosyl-aniline tethered alkynyl ketones under transfer hydrogenation conditions to give hydroquinolines is developed.

New chiral diene ligand, Fc,Ph-bod, showed higher enantioselectivity than Ph-bod in the rhodium-catalyzed asymmetric 1,4-addition of aryl- and alkenylboronic acids.

A copper-catalyzed methoxylation of unactivated (hetero)aryl C–H bonds has been developed.

A cyclic octapyrrole shows a strong chiroptical response upon complexation with an oligonucleotide that has high thymine content.

Oxidative C–H amination has proved to be an efficient strategy to construct pyrido[2′,1′:2,3]imidazo[4,5-b]indoles and their π-expanded analogs.

A novel synthesis of 1H-indazoles via copper-catalyzed cross-coupling/cyclization of 2-bromoaryl oxime acetates and amines is reported.

A simple and efficient approach for the synthesis of disubstituted carbazoles has been developed from o-haloanilines and terminal alkynes using a two-step strategy, namely, Sonogashira coupling and intramolecular cyclization.

Catalytic dehydrogenative aromatization has emerged as an efficient and environmentally friendly way to access functionalized arenes in recent years.