Zinc compounds biaryl synthesis

Among monoamines, both enantiomers of 1-phenylethylamine and their derivatives play a prominent role. They are commercially available, but can also be prepared by resolution of the racemate, obtainable by Leuckart- Wallach reaction of acetophenone1, with malic acid2 or, more conveniently, with tartaric acid in methanol3. They are used as chiral additives for the addition of zinc alkyls to aldehydes in Section D. 1.3.1.4., as copper complexes for the synthesis of biaryls in Section B.2., as lithium salts for enantioselective deprotonation in Section C., and as imines in Sections D.1.1.1.3.1., D.1.1.1,4.. D.1.4.4., D.1.5.2., D.1.5.8., D. 1.6.1.2.1., D.2.3.I., and D.8. A general procedure for the synthesis of imines from carbonyl compounds and primary amines, with many examples of both chiral carbonyl compounds and chiral amines is given in reference 4. 

Quinolinyl moiety has been applied in the Negishi reaction either as an electrophile or as nucleophile. 2- or 4-substituted quinolinyl triflates or bromides have been used extensively for introduction of aromatic rings at the C2 or C4 positions of the heterocycle. In a representative example, Murata et al. employed a Negishi reaction in his effort toward the formal synthesis of antitumor compound camptothecin. In accordance to that, 2-chloropyridine was allowed to react with lithium naphthalenide, followed by zinc chloride, to afford the corresponding zinc pyridine salt. Reaction of the resulting organozinc intermediate with 2-chloro-3-quinoline carboxylate provided the hetero biaryl core of camptothecin. ... 

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