Synthesis of Azabipyridine and Azaterpyridine Building Blocks for Multitopic Binding
摘要:
We describe the synthesis of four bromo-substituted azabipyridines and two bromo-substituted azaterpyridines through a series of palladium-catalyzed cross-coupling reactions. Both the azabipyridine and azaterpyridine heterocycles contain two orthogonal binding motifs, the value of which has been demonstrated recently in a nanomechanical switch for triggering organocatalysis. The bromo functionality allows heterocyclic ligands to be attached to larger frameworks.
The present application relates to mixed Mg/Li amides of the general formula
R1R2N-MgX·zLiY (I),
wherein
R1, R2 and R3 independently are selected from substituted or unsubstituted aryl or heteroaryl containing one or more heteroatoms, linear, branched or cyclic, substituted or unsubstituted alkyl, alkenyl, alkynyl, or derivatives thereof, and, for R1 and R2 only, the silyl derivatives thereof; one of R1 and R2 may be H; or R1 and R2 together can be part of a cyclic or polymeric structure;
X and Y independently are selected amongst others from the group consisting of F; Cl; Br; I; CN; SCN; NCO; and z > 0, as well as a process for the preparation of the mixed Mg/Li amides and the use of these amides, e.g. as bases.
N′‐tetramethylethylenediamine) or InCl3 (0.33 equiv) with [Li(tmp)] (tmp=2,2,6,6‐tetramethylpiperidino; 1.5 or 1.3 equiv, respectively) were compared with the previously described mixture of ZnCl2⋅TMEDA (0.5 equiv) and [Li(tmp)] (1.5 equiv) for their ability to deprotonate anisole, benzothiazole, and pyrimidine. [(tmp)3CdLi] proved to be the best base when used in tetrahydrofuran at room temperature, as demonstrated
Deprotonative Metalation of Substituted Benzenes and Heteroaromatics Using Amino/Alkyl Mixed Lithium-Zinc Combinations
作者:Katia Snégaroff、Shinsuke Komagawa、Floris Chevallier、Philippe C. Gros、Stéphane Golhen、Thierry Roisnel、Masanobu Uchiyama、Florence Mongin
DOI:10.1002/chem.201000543
日期:2010.7.19
Different homoleptic and heteroleptic lithium–zinccombinations were prepared, and structural elements obtained on the basis of NMR spectroscopic experiments and DFT calculations. In light of their ability to metalate anisole, pathways were proposed to justify the synergy observed for some mixtures. The best basic mixtures were obtained either by combining ZnCl2⋅TMEDA (TMEDA=N,N,N′,N′‐tetramethylethylenediamine)
This communication describes the deproto-metalation of a large range of aromatics including heterocycles using a newly developed lithium–cadmium base; the reaction proceeds at room temperature with an excellent chemoselectivity and efficiency, and proved to be regioselective in most cases.
organocatalyst to DS1–DS3 generates catalytic three‐component machineries. By using a conjugate addition as a probe reaction, we observed a correlation between the operating speed of the slider‐on‐deck systems and the yields of the catalytic reaction. As the thermodynamic binding of the slider decreases, both the frequency of the sliding motion and the yield of the catalytic reaction increase.