A series of novel chiral diene ligands (1R,4S)-L₁, which are based on the bicyclo[2.2.1]heptadiene skeleton and are substituted with methyl and an ester group at the bridgehead carbons, were synthesized through rhodium-catalyzed asymmetric arylative bis-cyclization of 1,6-enyne 1 as a key step. The rhodium catalyst with one of the (1R,4S)-L₁ ligands was used for the asymmetric bis-cyclization of 1 giving bicyclic product (1S,4R)-2 of 99% ee, which is a synthetic precursor of (1S,4R)-L₁ ligands.

中文翻译：

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通过铑催化的1,6-烯炔的不对称芳基双环化不对称合成手性双环[2.2.1]庚-2,5-二烯配体

通过铑合成了一系列基于双环[2.2.1]庚二烯骨架并在桥头碳上被甲基和酯基取代的新型手性二烯配体(1 R, 4 S ) -L ₁。作为关键步骤，催化 1,6-烯炔1 的不对称芳基双环化。铑催化剂用的一（1个R， 4小号）-L ₁被用于的不对称双-环化的配体1个得到双环产物（1 S， 4 - [R ）-2 99％ee值，这是一种合成前体(1 S, 4 R) -L ₁配体。