Diisopinocampheylboron trifluoromethanesulfonate

Related Reagents. (+)-S-Chlorodiisopinocampheylborane Diisopinocampheylboron Trifluoromethanesulfonate Dilongi-folylborane (/ ,/J)-2,5-Dimethylborolane B-Methoxydiiso-pinocampheylborane Monoisopinocampheylborane. 

Alternate Name diisopinocampheylboron triflate Ipc2BOTf. Physical Data colorless, viscous oil bp 150°C/0.01 mmHg ( bulb-to-bulb distillation ) (—)Ipc2BOTf [ctJo —43.5° (c = 30.4, hexane) B NMR (hexane) broad singlet at 5 = 60 ppm (with reference to BF3 OEt2). 

Solubility highly sol in both polar and nonpolar aprotic solvents, e.g. diethyl ether, THF, dichloromethane, pentane, hexane, etc. 

Boron Azaenolates from Oxazolines. The reagent is useful for asymmetric aldol condensations of achiral oxazolines. Treatment of 2-ethyl-4-dimethyl-2-oxazoline with IpC2BOTf in the presence of a tertiary amine furnishes a boron azaenolate. Without isolation, treatment with an aldehyde in ether at —78 °C provides an alkylated oxazoline, which is hydrolyzed and converted to p-hydroxy ester via treatment with Diazomethane. Although the yields for the four-step sequence are only moderate, the anti selectivities of the hydroxy acids are excellent with enantioselec-tivities of 77-85% ee (eq 1).  

A list of General Abbreviations appears on the front Endpapers 

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