Synthesis of polycyclic indoles via organocatalytic bicyclization of α-alkynylnaphthalen-2-ols with nitrones

A new organocatalytic bicyclization of α-alkynylnaphthalen-2-ols with nitrones was first reported, leading to the convergent synthesis of polycyclic indoles with substantial substitution diversity in generally good yields through scission of the N-O bond of nitrones via [3,3]-sigmatropic rearrangement. This transformation showcases the use of a quinine catalyst in a complicated cascade system that has been shown to effectively construct polycyclic heterocycles via alkyne difunctionalization.

Visible-Light-Mediated [2+2+1] Carbocyclization Reactions of 1,7-Enynes with Bromofluoroacetate to Form Fused Monofluorinated Cyclopenta[c]quinolin-4-ones

Herein, we describe a new protocol for photoinduced radical [2+2+1] carbocyclization reactions of 1,7-enynes with bromofluoroacetate. These reactions, which proceed via a cascade involving fluoroalkylation, 6-exo-dig and 5-endo-trig cyclizations, H-transfer step, and oxidative dehydrogenation, provide an efficient and general route to a variety of fused monofluorinated cyclopenta[c]quinolin-4-one derivatives.

Photo-driven haloazidation cyclization of 1,5-enynes having cyano groups with TMSN3 and NIS/NCS/NBS under metal-free conditions

A visible-light-driven three-component haloazidation cyclization of 1,5-enynes having cyano groups with TMSN₃ and N-iodo(bromo/chloro)succinimide (NIS/NCS/NBS) under metal-free conditions was developed.

Cu(ii)-Catalyzed formal [4 + 2] cycloaddition between quinone methides (QMs) and electron-poor 3-vinylindoles

A new Cu(ii)-catalyzed formal [4 + 2] cycloaddition between quinone methides (QMs) including para-quinone methides (p-QMs) and ortho-quinone methides (o-QMs) and electron-poor 3-vinylindoles was established.

Radical-mediated oxidative annulations of 1,n-enynes involving C–H functionalization

Recent progress in oxidative annulations of 1,n-enynes involving C–H functionalization is summarized.

Photoinduced double [2 + 2] cycloaddition relay of yne–allenones for highly diastereoselective synthesis of hexacyclic 1-naphthols

A new photoinduced photocatalyst-free energy-transfer strategy for double [2 + 2] cycloaddition relay of yne–allenones is reported for the first time and used to produce a series of hitherto unreported hexacyclic 1-naphthols.

Generation of (Z)-β-alkenyl alkylsulfones via a copper-catalyzed decarboxylative alkylsulfonylation

A copper-catalyzed three-component reaction of acrylamides, sulfur dioxide and phenyliodine(iii) dicarboxylates is developed. The conversion using phenyliodine dicarboxylates as alkyl radical precursors provides diverse (Z)-β-alkenyl alkylsulfones.

tert-Butyl peroxide (TBHP)/KI-mediated dual C(sp2)-H bond amination of arylamines with α-diazo carbonyls toward 1,2,4-benzotriazines

A new radical-induced dehydrogenative heterocyclization of arylamines with α-diazo carbonyls has been established under metal-free oxidative conditions, enabling two-fold C(sp2)-H bond amination to access a wide range of functionalized 1,2,4-triazine derivatives with generally good yields by combining KI/tert-butyl peroxide (TBHP). The present protocol features wide substrate scope, commercial accessibility, and mild reaction conditions. Mechanistic details of this radical process are rendered by conducting systematic theoretical calculations.

Layer-by-Layer Assembly: Recent Progress from Layered Assemblies to Layered Nanoarchitectonics

As an emerging concept for the development of new materials with nanoscale features, nanoarchitectonics has received significant recent attention. Among the various approaches that have been developed in this area, the fixed-direction construction of functional materials, such as layered fabrication, offers a helpful starting point to demonstrate the huge potential of nanoarchitectonics. In particular, the combination of nanoarchitectonics with layer-by-layer (LbL) assembly and a large degree of freedom in component availability and technical applicability would offer significant benefits to the fabrication of functional materials. In this Minireview, recent progress in LbL assembly is briefly summarized. After introducing the basics of LbL assembly, recent advances in LbL research are discussed, categorized according to physical, chemical, and biological innovations, along with the fabrication of hierarchical structures. Examples of LbL assemblies with graphene oxide are also described to demonstrate the broad applicability of LbL assembly, even with a fixed material.

Silver-catalyzed decarboxylative radical cascade cyclization toward benzimidazo[2,1-a]isoquinolin-6(5H)-ones

A simple and efficient decarboxylative radical addition/cyclization strategy was developed, by which a wide range of benzimidazo[2,1-a]isoquinoline-6(5H)-ones were prepared in one-pot via reaction of functionalized 2-arylbenzoimidazoles and carboxylic acids in the presence of K2S2O8/AgNO3 under mild reaction conditions.

Photocatalytic decarboxylative [2 + 2 + 1] annulation of 1,6-enynes with N-hydroxyphthalimide esters for the synthesis of indene-containing polycyclic compounds

An efficient photoredox-mediated [2 + 2 + 1] annulation of 1,6-enynes with N-hydroxyphthalimide esters was reported for the synthesis of spiro and non-spiro indene-containing polycyclic frameworks.

Copper-catalyzed one-pot three-component thioamination of 1,4-naphthoquinone

A concise one-pot three-component thioamination of 1,4-naphthoquinone with thiols and amines was developed to synthesize 2-amino-3-thio-1,4-naphthoquinones.

Oxidative tandem annulation of 1-(2-ethynylaryl)prop-2-en-1-ones catalyzed by cooperative iodine and TBHP

Metal-free I₂-catalyzed tandem annulation of 1,6-enynes to access 1H-cyclopropa-[b]naphthalene-2,7-diones using TBHP is presented.

Recent advances of 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) in photocatalytic transformations

In this review, the recent advances of the application of 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) as a photoredox catalyst in the past three years (2016–2018) for various organic reactions are summarized.