Rh(III)-catalyzed directed C–H bond amidation of ferrocenes with isocyanates

• Satoshi Takebayashi,
• Tsubasa Shizuno,
• Takashi Otani and
• Takanori Shibata

Beilstein J. Org. Chem. 2012, 8, 1844–1848, doi:10.3762/bjoc.8.212

• reaction setup and is required to prevent the redox reaction between AgBF4 and 1a [24]. However, the use of [RhCp*(MeCN)3](BF4)2 [17] resulted in lower yield likely due to the coordination of MeCN (Table 1, entry 6). The yield significantly increased when the combination of [RhCp*(OAc)2(H2O)] [25] and 2

Organocatalytic C–H activation reactions

• Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

• organocatalytic asymmetric C–H activation reaction was disclosed by Kim and co-workers for the synthesis of chiral tetrahydroquinolines 14 (Scheme 10) [24]. ortho-(Dialkylamino)cinnamaldehydes were employed as the substrates for this aminocatalytic intramolecular redox reaction. The authors first demonstrated a

• . Mechanism for the indole-annulation cascade reaction. Synthesis of N-alkylpyrroles and δ-hydroxypyrroles. Synthesis of N-alkylindoles 9 and N-alkylindolines 10. Mechanistic study for the N-alkylpyrrole formation. Benzoic acid catalysed decarboxylative redox amination. Organocatalytic redox reaction of ortho

• -(dialkylamino)cinnamaldehydes. Mechanism for aminocatalytic redox reaction of ortho-(dialkylamino)cinnamaldehydes. Asymmetric synthesis of tetrahydroquinolines having gem-methyl ester groups. Asymmetric synthesis of tetrahydroquinolines from chiral substrates 18. Organocatalytic biaryl synthesis by Kwong, Lei

Recent developments in gold-catalyzed cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2011, 7, 1075–1094, doi:10.3762/bjoc.7.124

• alternative procedure for the generation and subsequent cycloaddition of azomethine ylide intermediates under gold catalysis. Importantly, they demonstrated that the intramolecular attack of a nitrone oxygen to a tethered gold-activated alkyne leads, by means of an internal redox reaction, to an α-carbonyl

Addition of lithiated enol ethers to nitrones and subsequent Lewis acid induced cyclizations to enantiopure 3,6-dihydro-2H-pyrans – an approach to carbohydrate mimetics

• Fabian Pfrengle and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2010, 6, No. 75, doi:10.3762/bjoc.6.75

• (Scheme 9). With the objective of preparing a diaminopyran, we attempted to substitute the bromide atom in compound 15 with the azido group. Surprisingly, instead of the desired α-azido ketone, the formation of nitrone 21 was observed, which apparently involves an unusual internal redox reaction (Scheme

• moiety of trans-5a leading to products 13–15. Bromination of bicyclic dihydropyran trans-5b affording 16. Synthesis of epoxypyran 18 by bromination of cis-5d. Oxidative cleavage of dihydropyran 19 to lactone 20. Transformation of α-bromoketone 15 into nitrone 21 by an internal redox reaction