Recent advances in carbocupration of α-heterosubstituted alkynes

• Ahmad Basheer and
• Ilan Marek

Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77

• adducts (Scheme 22). Hydrolysis, alkylation, acylation, halogenation and stannylation proceed stereoselectively to afford synthetically useful intermediates [56][57]. Under similar conditions, 1-substituted alkynylsilanes do not undergo the carbometalation reaction. Only when 1-substituted-2

Palladium- catalyzed cross coupling reactions of 4-bromo- 6H-1,2-oxazines

• Reinhold Zimmer,
• Elmar Schmidt,
• Michal Andrä,
• Marcel-Antoine Duhs,
• Igor Linder and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2009, 5, No. 44, doi:10.3762/bjoc.5.44

• -hexyne provided alkynyl-substituted pyridine derivative 12 thus demonstrating the potential of this approach for the synthesis of pyridines. Keywords: alkyne; halogenation; 1,2-oxazines; palladium catalysis; pyridines; Introduction A broad range of synthetic applications demonstrates that 1,2-oxazine

• , we describe our results dealing with the halogenation of 6H-1,2-oxazines 1 and the use of the resulting products as precursors in palladium-catalyzed cross coupling reactions. Results and Discussion Not much is known about halogenated 6H-1,2-oxazines and only a few mostly inefficient procedures are

The use of silicon- based tethers for the Pauson- Khand reaction

• Adrian P. Dobbs,
• Ian J. Miller and
• Saša Martinović

Beilstein J. Org. Chem. 2007, 3, No. 21, doi:10.1186/1860-5397-3-21

• order to achieve this it was thought to form each of the 'arms' of the acetal in separate synthetic steps (Scheme 15). The first stage of the reaction was silyl ether formation. The alkyne 'arm' of the acetal was introduced first, as it was feared that during the next, halogenation step, halogenation of