A palladium-catalyzed dehydrogenative coupling between diarylamines and olefins has been discovered for the synthesis of substituted indoles. This intermolecular annulation approach incorporates readily available olefins for the first time and obviates the need of any additional directing group. An ortho palladation, olefin coordination, and β-migratory insertion sequence has been proposed for ...

This paper describes a convenient approach to the 7-aza-des-A-steroid (6,6a,7,8,9,9a-hexahydro-5H-cyclopenta[h]quinoline) scaffold starting from Grundmann's ketone using two different pyridine annulation protocols. The biological evaluation of the pyridine and pyridinium products revealed that these compounds unexpectedly do not interfere with ergosterol and cholesterol biosynthesis. The pyridi...

Conjugated nitroalkenes and nitrodienes undergo smooth α-hydrazination with azodicarboxylates through an imidazole catalyzed carbon-heteroatom bond formation under Morita-Baylis-Hillman conditions. The resulting hydrazinonitroalkenes take part in 1,3-dipolar cycloaddition with azide under mild conditions to give hydrazinotriazoles. A [3 + 2] annulation with phenols and naphthols involving Micha...

En droit administratif général, un acte unilatéral qui exécute ou applique une loi doit lui être conforme. Dans le cas contraire, son annulation par l’autorité administrative juge compétent est donc possible à l’occasion d’un recours. Cependant, l’introduction du recours respecter délai contentieux.

The development of a triflimide-catalyzed annulation of benzylic alcohols with allylsilanes for the synthesis of indane or tetralin structures is reported. In this fragment coupling reaction, complexity is built rapidly from readily available starting materials to yield diverse sets of products with up to three contiguous stereocenters. Indanes or tetralins can be generated from common precurso...

An enantioselective [3 + 2] annulation of donor–acceptor aziridines with aldehydes has been realized using a Nd(OTf)3/N,N0-dioxide/LiNTf2 catalyst system, providing various chiral cis-1,3-oxazolidines inmoderate to good yields with high levels of stereocontrol. A relay catalytic process is proposed where LiNTf2 promotes the formation of azomethine ylide intermediates, and a chiral Nd(III)–N,N0-...

An efficient synthesis of the tetracyclic steroid core, 19, of rhodexin A and sarmentogenin is reported. An initial inverse-electron-demand Diels-Alder reaction of the acyldiene 6 with the silyl enol ether 7a gave the cycloadduct 8 with the required four contiguous stereocenters in a single step. This compound was then transformed into the methylated enedione 13 which afforded after a reductive...

The development of an efficient method for the construction of biologically relevant sultams is described, which represents the first case of cobalt-promoted C-H/N-H functionalization of sulfonamides with allenes. This newly developed annulation reaction demonstrated good functional group tolerance and excellent regioselectivity. Both terminal monosubstituted allenes and internal disubstituted ...

The title compound, C(21)H(18)N(2)O(2), was synthesized using a novel tandem annulation reaction between (1H-benzimidazol-2-yl)(phen-yl)methanone and (E)-ethyl 4-bromo-but-2-enoate under mild conditions. The dihedral angles between the mean planes of the five-membered imidazole ring and the pyridine, benzene and phenyl rings are 0.45 (6), 1.69 (1) and 70.96 (8)°, respectively. In the crystal, m...

The development of an efficient catalytic system for enantioselective carbon-carbon bond formation by 1,4-addition of organometallic reagents (organolithium, Grignard, and organozinc reagents) to enones is a major challenge in organic synthesis. This Account presents the breakthrough realized in this field using chiral phosphoramidite ligands for copper-catalyzed dialkylzinc additions. Applicat...