George Josemon, Ward Jas S, Sherburn Michael S
Research School of Chemistry , Australian National University , Canberra , ACT 2601 , Australia . Email:
Chem Sci. 2019 Sep 12;10(43):9969-9973. doi: 10.1039/c9sc03976g. eCollection 2019 Nov 21.
The first general synthetic approach to substituted [3]- and higher dendralenes is reported. Fifty-one mono- through to penta-substituted dendralenes carrying alkyl-, cycloalkyl-, alkenyl-, alkynyl-, aryl- and heteroaryl-substitutents are accessed, and the first ()/()-stereoselective syntheses of dendralenes are reported (twenty-eight examples). The approach involves twofold Pd(0)-catalyzed Negishi couplings of 1,1-dibromoalkenes with alkenylzinc reagents, and exploits both substrate- and catalyst-controlled aspects of chemo-, regio- and stereoselectivity in the two C(sp)-C(sp) bond forming steps. The value of the new hydrocarbons in rapid structural complexity generation is demonstrated through their deployment in unprecedented diene- and triene-transmissive pericyclic reaction sequences.
报道了一种用于合成取代[3] - 及更高碳数的树状烯的通用合成方法。制备了51种带有烷基、环烷基、烯基、炔基、芳基和杂芳基取代基的单取代至五取代树状烯，并报道了树状烯的首例（）/（）-立体选择性合成（28个实例）。该方法涉及1,1 - 二溴烯烃与烯基锌试剂的双重钯（0）催化的根岸偶联反应，并在两个C（sp）-C（sp）键形成步骤中利用了化学、区域和立体选择性的底物控制和催化剂控制方面。通过将这些新型烃类用于前所未有的二烯和三烯传递周环反应序列，证明了它们在快速构建结构复杂性方面的价值。
