Protocol for Sonogashira coupling of alkynes and aryl halides via nickel catalysis.

Alkynes are widely present in natural products and pharmaceutical compounds. Here, we present a protocol for nickel-catalyzed cross-coupling of terminal alkynes with aryl iodides or bromides for constructing a C(sp2)-C(sp) bond. We describe steps for reagent preparation, reaction setup, purification process, and product characterization. We also detail procedures for obtaining a single crystal of 6-(phenylethynyl)-1-(phenylsulfonyl)-1H-indole (3b). The application of this protocol is limited to aryl bromide and iodide. For complete details on the use and execution of this protocol, please refer to Chen et al.1.

Synthesis of 3-SCF2H-/3-SCF3-chromones via Interrupted Pummerer Reaction/Intramolecular Cyclization Mediated by Difluoromethyl or Trifluoromethyl Sulfoxide and Tf2O.

The reaction of alkynyl aryl ketones bearing an o-methoxy group with difluoromethyl sulfoxide in the presence of Tf2O was found to conveniently afford the corresponding 3-SCF2H-substituted chromones. The combining use of difluoromethyl sulfoxide/Tf2O could represent the first reagents system that can introduce the biologically important SCF2H moiety under base-free conditions via an interrupted Pummerer reaction. The same protocol could also be applied to the synthesis of 3-SCF3-substituted chromones by replacing difluoromethyl sulfoxide with trifluoromethyl sulfoxide and CH3CN with toluene.

Chemoselective Synthesis of Sulfenylated Spiroindolenines from Indolyl-ynones via Organosulfenyl Chloride-Mediated Dearomatizing Spirocyclization.

A metal-free sulfenylation/spirocyclization of indolyl-ynones realized by organosulfenyl chloride, generated in situ from the reaction of disulfides and PhICl2, is presented. This cascade one-pot process enables a chemoselective synthesis of diverse sulfenylated spiroindolenines depending on the substituent pattern at the two-position of indolyl-ynones.

Construction of 2-Arylbenzo[4,5]thieno[2,3-d]thiazole Skeleton via CuCl/S-Mediated Three-Component Reaction.

An exclusive thiophene-fused polycyclic π-conjugated 2-arylbenzo[4,5]thieno[2,3-d]thiazole skeleton was constructed via a one-pot CuCl-mediated three-component reaction, using 2-(2-bromophenyl)acetonitrile and aromatic aldehydes as substrates and elemental sulfur as sulfur source in the presence of K2CO3 and 1,10-phen in DMSO. A plausible reaction mechanism was proposed, which involved formation of benzo[b]thiophen-2-amines through cyclization of 2-bromophenyl acetonitrile and sulfur, and subsequent intramolecular condensation/dehydrogenation with aromatic aldehydes.

Regioselective Chlorolactonization of Styrene-Type Carboxylic Esters and Amides via PhICl2-Mediated Oxidative C-O/C-Cl Bond Formations.

A facile method employing styrene-type carboxylic esters or amides in the presence of PhICl2 in CH3CN was developed to achieve the synthesis of 6-endo products 3,4-dihydroisocoumarins or 3,4-dihydroisocoumarin-1-imines in good to high yields. This metal-free regioselective intramolecular chlorolactonization process was proposed to involve a PhICl2-mediated oxidative C-O bond formation followed by C-Cl bond formation.