Synthesis and structural properties of -diselenopyrazines.

Recently, dithienopyrazines have emerged as promising building blocks in the field of materials science, showcasing their potential as hole-transport materials in organic electronic devices. Herein, we report the synthesis of its heavier analogues, the diselenopyrazines, along with an analysis of their optoelectronic and structural properties. In the acquired crystal structures, interesting molecular packing motifs suitable for potential device fabrication were observed.

Synthesis of 2,3-Disubstituted 4-Ethoxycarbonyl-β-carbolin-1-ones: Application to the Synthesis of SL651498 and Its Analogue.

Synthesis of 2,3-disubstituted 4-ethoxycarbonyl-β-carbolin-1-ones is developed using palladium-catalyzed intramolecular amination of 3-amino-4-(2-bromophenyl)-2-pyridones prepared by the conjugate addition reaction of diethyl 2-aminomalonate to alkynyl imines. The method was applied to the total syntheses of SL651498 exhibiting anxiolytic activity and its analogue.

Domino 1,4- and 1,6-Addition Reactions of Ketene Silyl Acetals to Dialkynyl Imines Promoted by Aluminum Chloride: Synthesis of Multifunctionalized β-Lactams.

Domino 1,4- and 1,6-addition reactions of ketene silyl acetals to dialkynyl imines are disclosed. Aluminum chloride promoted domino 1,4- and 1,6-addition reactions of ketene silyl acetals to dialkynyl imines to give a variety of alkenyl iminocyclobutenones in moderate to good yields. The chemoselective reduction of alkenyl iminocyclobutenones and the subsequent thermal rearrangement of resulting alkenyl aminocyclobutenones in the presence of appropriate amines provided cis or trans multifunctionalized β-lactams in moderate to high yields with good to high diastereoselectivities.

Titanium Tetraiodide/Trimethylsilyl Iodide Synergistically Induced Cyclization of -(2-Cyanophenyl)benzamides into 2-Aryl-4-iodoquinazolines.

Synthesis of 2-aryl-4-iodoquinazolines is developed using titanium tetraiodide/trimethylsilyl iodide synergistically induced cyclization of -(2-cyanophenyl)benzamides. The cyclization reactions proceeded to give the 2-aryl-4-iodoquinazolines in moderate to high yields. Remarkable synergetic effect of titanium tetraiodide and trimethylsilyl iodide was observed to promote the cyclization.

Use of N-allylidene-1,1-diphenylethanamine as a latent acrolein synthon in the double nucleophilic addition reaction of ketene silyl (Thio)acetals and allylborolanes.

In the presence of silica gel and water, a mixture of ketene silyl acetals and 2-allyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane underwent 1,4- and subsequently 1,2-addition with N-allylidene-1,1-diphenylethanamine to give delta-hydroxyesters in good yields, where the allylideneamine was successfully used as an acrolein equivalent.

Stereodivergent synthesis of beta-lactams using thermal rearrangement of aminocyclobutenones.

In the present study, the stereodivergent synthesis of both cis- and trans-beta-lactams is presented using the following three reactions: iminocyclobutenone formation, chemoselective reduction of imino groups, and thermal rearrangement of aminocyclobutenones as crucial steps, in which the starting materials, iminocyclobutenones, were readily synthesized using conjugate addition reactions of alkynyl imines with ketene silyl acetals in good yields.

Conjugated imines and iminium salts as versatile acceptors of nucleophiles.

Growing interests in nitrogen-containing molecules involving bioactive and functional materials have stimulated the recent development of synthetic methodologies where nucleophilic addition reactions to imino carbons are utilized in crucial steps. This article summarizes double nucleophilic addition reactions with alpha,beta-unsaturated aldimines, addition reactions using alkynyl imines, "umpoled" reactions of alpha-imino esters, and the use of iminium salts as reactive electrophiles.

Synthesis of N-allylideneamines and their use for the double nucleophilic addition of ketene silyl (thio)acetals and trimethylsilyl cyanide.

N-Allylideneamines 1a, b were prepared from acrolein and diphenylethyl or trityl amine in the presence of Ti(OEt)4. Double nucleophilic addition of various ketene silyl (thio)acetals and trimethylsilyl cyanide to these imines proceeded efficiently to give, after workup with TFA, homoglutamic acid derivatives 3 and valerolactam 5.

Novel 2-pyridone synthesis via nucleophilic addition of malonic esters to alkynyl imines.

[reaction: see text] A novel 2-pyridone synthesis via nucleophilic addition of malonic esters to alkynyl imines has been developed. The reaction of dialkylalkyl sodiomalonates with alkynyl imines provided 2-pyridones in good to excellent yields.