Diamidobinaphthyl dilithium salt

A dimeric proline-derived diamidobinaphthyl dilithium salt has been introduced as the first example of a chiral main group metal-based catalyst for asymmetric hydroami-nation-cyclization reactions of aminoalkenes.256... 

The proline derived diamidobinaphthyl dilithium salt (S,S,S) 41, which is dimeric in the solid state and can be prepared via deprotonation of the corresponding tetraamine with nBuLi, represents the first example of a chiral main group metal based catalyst for asymmetric intramolecular hydroamination reactions of aminoalk enes [72]. The unique reactivity of (S,S,S) 41, which allowed reactions at or below ambient temperatures with product enantioselectivities of up to 85% ee (Scheme 11.12) [76], is believed to derive from the proximity of the two lithium... 

The diamidobinaphthyl dilithium salt (R)-67 was generated in situ from the free diaminobinaphthyl ligand and 2.5 equiv. of LiCH2SiMe3 [135]. This system lacks a chelating sidearm and gave predominantly low enantioselectivities except for the gem-diphenyl-substituted aminopentene. Unfortunately, the cyclization of aminoalkenes seems to be limited to activated gem-dialkyl substituted [69] aminopentene... 

The hydroamination/cyclization of terminal aminodienes can also be catalyzed by chiral diamidobinaphthyl dilithium salts with up to 72% ee (Scheme 19) [134, 135]. Although the EJZ selectivity of the product is moderate in most cases, both diastereoisomers can be obtained with comparable enantiomeric excess. 

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