What are the differences between eliminations of early and late transition metals? DFT mechanistic insights into the titanium-catalyzed synthesis of pyrroles from alkynes and diazenes

The linear codimerization of acrylates and alkynes to produce 1,3-dienes is successfully demonstrated using a nickel catalyst in association with 2-aminopyridine as an additive.

A simple and efficient palladium-catalyzed three-component domino reaction of bromothiophenes with internal alkynes has been developed to produce benzo[b]thiophenes in moderate to good yields.

2-Vinylic cyclic 1,3-alkadienes can be obtained with moderate to good yields via the Cp*RuCl(PPh3)2-catalyzed coupling reaction of alkynes with cyclic allenes.

Hydrozirconation of alkynes with Cp2ZrH(Cl) (Schwartz reagent) generates vinyl zirconium species reliably, stereospecifically, and regioselectively. These organometallic reagents can participate in cross-coupling reactions, conjugate and nucleophilic additions, and can undergo carbonylation and halogenation.1 Hydrozirconation of terminal alkynes often proceeds with >50:1 selectivity to form the...

Alkynes generally serve as C2 synthons in transition-metal-catalyzed C−H annulations, herein, exploiting electron-deficient alkynes unconventional C1 synthons, the chemo- and regiospecific synthesis of functionalized 1H-imidazo[1,5-a]indol-3(2H)-ones via a redox-neutral rhodium(III)-catalyzed [4+1] annulation N-carbamoyl indoles has been achieved. This process is characterized by high regiosele...

A practical 1,2,3,4-tetrahydroisoquinoline (THIQ)-mediated synthesis of 1,3-disubstituted allenes from terminal alkynes and aldehydes under mild conditions in the presence of CuBr first and then ZnI2 was reported. This telescoped allene synthesis reaction includes three consecutive steps and two reactions: first, a room-temperature CuBr-catalyzed synthesis of propargylamines, exo-yne-THIQs, fro...

Self-assembled monolayers (SAMs), prepared by reaction of terminal n-alkynes (HC≡C(CH2)nCH3, n = 5, 7, 9, and 11) with Au(111) at 60 °C were characterized using scanning tunneling microscopy (STM), infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and contact angles of water. In contrast to previous spectroscopic studies of this type of SAMs, these com...