One-pot two-step synthesis of 1-position arylated 1,3-disubstituted isoquinoline N-oxides

Silver-catalysed reactions of alkynes: recent advances

Silver is a less expensive noble metal. Superior alkynophilicity due to π-coordination with the carbon-carbon triple bond makes silver salts ideal catalysts for alkyne-based organic reactions. This review highlights the progress in alkyne chemistry via silver catalysis primarily over the past five years (ca. 2010-2014). The discussion is developed in terms of the bond type formed with the acetylenic carbon (i.e., C-C, C-N, C-O, C-Halo, C-P and C-B). Compared with other coinage metals such as Au and Cu, silver catalysis is frequently observed to be unique. This critical review clearly indicates that silver catalysis provides a significant impetus to the rapid evolution of alkyne-based organic reactions, such as alkynylation, hydrofunctionalization, cycloaddition, cycloisomerization, and cascade reactions.

A room-temperature protocol to access isoquinolines through Ag(i) catalysed annulation of o-(1-alkynyl)arylaldehydes and ketones with NH4OAc: elaboration to berberine and palmatine

A silver catalysed protocol for the synthesis of a wide range of isoquinolines from o-(1-alkynyl)arylaldehydes has been developed under mild conditions and elaborated to the synthesis of berberine and palmatine.

Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands

A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent at ambient temperature and low catalyst loading.

Advances in direct C–H arylation of 5,5- 6,5- and 6,6-fused-heterocycles containing heteroatoms (N, O, S)

This report aims to review the advances made in C–H arylation of 5,6, 6,6 and 5,5 fused-heterocyclic systems.

Synthesis of 2-trifluoromethylpyrazolo[5,1-a]isoquinolines via silver triflate-catalyzed or electrophile-mediated one-pot tandem reaction

An efficient one-pot tandem cyclization/[3 + 2] cycloaddition reaction of N’-(2-alkynylbenzylidene)hydrazides with ethyl 4,4,4-trifluorobut-2-ynoate under silver triflate-catalyzed or electrophile-mediated conditions is described. Various trifluoromethylated pyrazolo[5,1-a]isoquinolines were afforded in moderate to excellent yield by this developed method.

AgOTf-catalyzed one-pot reactions of 2-alkynylbenzaldoximes with α,β-unsaturated carbonyl compounds

AgOTf-catalyzed one-pot reactions of 2-alkynylbenzaldoximes with various α,β-unsaturated carbonyl compounds under mild conditions are described, which provides a facile and efficient pathway for the synthesis of 1-alkylated isoquinoline derivatives. The method tolerates a wide range of substrates and allows for the preparation of the products of interest in moderate to excellent yields.

Pd-catalysed ortho-C-H Acylation/cross Coupling of 2-arylbenzo[d]thiazoles with Aldehydes Using tert-butyl Hydroperoxide as Oxidant

An efficient palladium-catalysed protocol for direct C–H bond acylation by cross coupling of 2-arylbenzo[d]thiazoles and aldehydes using tert-butyl hydroperoxide as the oxidant is reported. The process provides a useful method for the synthesis of aromatic ketones directly from aldehydes. In addition, the reaction can tolerate various functional groups in good yield with high regioselectivity.

New simple synthesis of ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thiones: Direct formation from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles

A new simple and efficient method to construct ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thione derivatives has been developed from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles under mild conditions, without the need for a metal catalyst. The newly developed method tolerates a wide range of substrates in moderate to excellent yields. Moreover, this method is advantageous over previous ones for the easy synthesis of reactants.