Preparation of functionalized organoaluminiums by direct insertion of aluminium to unsaturated halides.
The preparation of polyfunctional organometallics is important in organic synthesis as these reagents are very popular nucleophiles. The preparation of functionalized aluminium reagents by direct insertion of aluminium powder is in general not possible. Such a reaction would be of special importance owing to the low price of aluminium compared with magnesium (it is half the price), the low toxicity of this metal and the chemoselectivity of the resultant organoaluminium reagents. We have now found that by adding catalytic amounts of selected metallic chlorides (TiCl(4), BiCl(3), InCl(3) or PbCl(2)) in the presence of LiCl, aluminium powder inserts into various unsaturated iodides and bromides under mild conditions. These resulting new organoaluminium reagents undergo smooth Pd-catalysed cross-coupling and acylation reactions, as well as copper-catalysed allylic substitutions, affording various interesting products for pharmaceutical and material science applications.
Department Chemie und Biochemie, Ludwig-Maximilians-Universität München, Butenandtstrasse, München, Germany.
Tobias
T
Blümke
Yi-Hung
YH
Chen
Zhihua
Z
Peng
Paul
P
Knochel
D000535:Aluminum / Q000737:chemistry*; D002384:Catalysis; D006219:Halogens / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry; D018021:Lithium Chloride / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*
D006219:Halogens; D007202:Indicators and Reagents; D009942:Organometallic Compounds; D000535:Aluminum; D018021:Lithium Chloride