A convenient method for construction of polycyclic fused nitrogen-containing heterocycles has been developed. The methodology involves palladium-catalyzed intermolecular carbopalladation-annulation cascade reaction of haloaryl heterocyclic derivatives with different alkynes under relatively mild reaction conditions. Thus, the palladium-catalyzed cascade cyclization of bromophenyl derivatives of...

The one-carbon bridge stereochemistry of bicyclo[3.3.1]nonane products formed in the Robinson annulation reactions of 2-substituted cyclohex-2-enones was investigated. In contrast to previous reports, it was found that the major diastereomer formed places the one-carbon bridge substituent anti to the beta-keto ester/amide unit introduced in the Robinson annulation. This stereoselectivity appear...

The one-humped camel (Camelus dromedarius) is a seasonal breeder with a relatively short breeding period, when increased ovarian activity is exhibited (Shalash, 1965,1980; Nawito, Shalash, Hoppe ¿St Rakha, 1967 ; Novoa, 1970). In Israel, the normal breeding season occurs from December to early April. Female camels come into heat during this period and exhibit mainly follicular activity; there i...

a r t i c l e i n f o JEL classification: F12 F15 R11 R12 Keywords: Heterogeneous taste and quality Spatial selection Economic geography Agglomeration Home market effect In this paper, we develop an economic geography model in which firms sell product varieties with heterogeneous demands. We show that firms that sell products with higher demand choose to establish their plants in larger countri...

The reaction of a sec-nitrodienamine 3 with aldehyde compounds afforded 2-substituted 3-nitro-1,2-dihydropyridines 5, providing a heterocyclic annulation reaction.

A modular approach to 3-substituted 2-quinolones via a cascade annulation reaction between 4-nitroketones and hydrazines has been developed.

Phosphine-catalyzed [4+1] annulation of 2-tosylaminochalcones with allenoates has been achieved, giving trans-2,3-disubstitued indolines as major diastereoisomers in moderate to good yields.

A planar-chiral DMAP derivative catalyzes an intriguing [3 + 2] annulation reaction of silylated indenes to produce diquinanes that bear three contiguous stereocenters (one quaternary and two tertiary).

3-Substituted 2,5-dimethylpyrazines were synthesized in high yields via a one-pot cascade annulation of easily available propargyl amine with aldehydes catalyzed by Au(PPh2Cy)Cl.

A phosphine-catalyzed dearomatizing [3+2] annulation of isoquinolinium methylides with allenoates or allenones yields highly functionalized pyrroloisoquinolines with high regioselectivity and in viable yields.