A series of 10,13-disubstituted 16-membered macrolides was synthesized using nitroso Diels-Alder reactions of leucomycin A7. Despite the extensive constituent functionalities in leucomycin, the hetero cycloaddition reactions proceeded in a highly regio- and stereoselective fashion. Subsequent chemical modifications of the nitroso cycloadducts, including N-O bond reduction, were also conducted. ...

The aza-Diels-Alder cycloaddition of 1,2,4-triazines with alkynes offers a rapid and convenient method for the synthesis of highly substituted pyridines, but often requires harsh conditions and long reaction times. The present study offers a solution to these limitations by use of a temporary tether established by a Lewis acid-base complexation of in situ generated alkynylboranes and triazines ...

Enyne alcohols can react as precursors of either dienes or dienophiles with different substrates after hydroxylation and isomerization by gold catalysis. As such, oxa-bridged tricyclo[5.2.2.02,6]-undec-8-ene-3,5-dione derivatives have been obtained by the Diels–Alder reaction and tetrahydro-1H-furo[3,4-c]pyran derivatives could be accessed by the hetero-Diels–Alder cycloaddition.

A novel reaction of acylium and thioacylium ions, polar [4 + 2(+)] Diels-Alder cycloaddition with 1,3-dienes and O-heterodienes, has been systematically investigated in the gas phase (Eberlin MN, Cooks RG. J. Am. Chem. Soc. 1993; 115: 9226). This polar cycloaddition, yet without precedent in solution, likely forms cyclic 2,5-dihydropyrylium ions. Here we report the reactions of gaseous acylium ...

The first Diels-Alder cycloaddition of o-quinodimethane to SWNT has been performed under microwave irradiation.

Abstract The conversion of benzophenone methylhydrazone with bromine and pyridine into 1-[(methyldiazenyl)diphenylmethyl]pyridin-1-ium bromide followed by the solvolysis methanol provides a facile synthesis 1-(methoxydiphenylmethyl)-2-methyldiazene. acid-induced hydrolysis this N,O-ketal releases methyldiazenyl moiety as putative intermediate methyldiazenium ion. Reacting heterodienophile, ion ...

Regioselective Diels-Alder reactions of acyl-1,4-benzoquinones 1 with, severally, isoprene, trans-piperylene,1-acetoxy-1,3-butadiene and 1-methoxy-1,3-butadiene gave the corresponding adducts 2 in high yield. Treatment of the adducts 2 with manganese dioxide gave regiospecifically the corresponding 1,4-naphthoquinones 3. In several cases, the adducts of the acetylquinones afforded intermediates...

We explore the potential of the Diels-Alder cycloaddition for the functional tagging of DNA strands. A deoxyuridine triphosphate derivative carrying a diene at position 5 of the pyrimidine base was synthesized using a two-step procedure. The derivative was efficiently accepted as substrate in enzymatic polymerization assays. Diene carrying strands underwent successful cycloaddition with maleimi...

A metal-free and formal [2 + 2 + 2] cycloaddition of triynes has emerged recently as a novel methodology for the synthesis of fused tricyclic compounds via an intramolecular cascade propargylic ene reaction, Diels-Alder cycloaddition and tautomerization. DFT calculations on three model systems reveal that the ene reaction with low distortion energy makes the metal-free strategy feasible and, as...