Chiral compounds allylborations

Increasing interest is expressed in diastereoselective addition of organometallic reagents to the ON bond of chiral imines or their derivatives, as well as chiral catalyst-facilitated enantioselective addition of nucleophiles to pro-chiral imines.98 The imines frequently selected for investigation include N-masked imines such as oxime ethers, sulfenimines, and /V-trimcthylsilylimines (150-153). A variety of chiral modifiers, including chiral boron compounds, chiral diols, chiral hydroxy acids, A-sull onyl amino acids, and /V-sulfonyl amido alcohols 141-149, have been evaluated for their efficiency in enantioselective allylboration reactions.680... 

B-Allyldiisocaranylborane (3). This compound, prepared from (+ )-3-carene, undergoes even more enantioselective allylboration than does 1 to furnish chiral ho-moallylic alochols in 86-99% ee (six examples) ... 

Hoffmann has continued his pioneering work in asymmetric allylboration and synthesized several heterocyclic compounds (26). Soderquist has developed a new reagent, chiral 5-allyl-10-trimethylsilyl-9-borabicyclo[3.3.2]-decane for allylboration reactions (27). 

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