Molecular Design Institute and Department of Chemistry, New York University , New York, New York 10003, United States.
J Am Chem Soc. 2015 Oct 14;137(40):12984-9. doi: 10.1021/jacs.5b07257. Epub 2015 Oct 1.
In Nature, incompatible catalytic transformations are being carried out simultaneously through compartmentalization that allows for the combination of incompatible catalysts in tandem reactions. Herein, we take the compartmentalization concept to the synthetic realm and present an approach that allows two incompatible transition metal catalyzed transformations to proceed in one pot in tandem. The key is the site isolation of both catalysts through compartmentalization using a core-shell micellar support in an aqueous environment. The support is based on amphiphilic triblock copolymers of poly(2-oxazoline)s with orthogonal functional groups on the side chain that can be used to cross-link covalently the micelle and to conjugate two metal catalysts in different domains of the micelle. The micelle core and shell provide different microenvironments for the transformations: Co-catalyzed hydration of an alkyne proceeds in the hydrophobic core, while the Rh-catalyzed asymmetric transfer hydrogenation of the intermediate ketone into a chiral alcohol occurs in the hydrophilic shell.
在自然界中，通过分隔化同时进行不兼容的催化转化，这使得在串联反应中可以组合不兼容的催化剂。在此，我们将分隔化概念引入合成领域，并提出了一种方法，可使两种不兼容的过渡金属催化转化在一锅串联反应中进行。关键是通过在水相环境中使用核壳型胶束载体将两种催化剂进行位隔离。该载体基于具有侧链正交官能团的两亲性三嵌段共聚物聚（2-恶唑啉），可用于共价交联胶束并在胶束的不同区域共轭两个金属催化剂。胶束的核和壳为转化提供了不同的微环境：炔烃的共催化水合在疏水性核中进行，而中间酮的铑催化不对称转移氢化反应在亲水性壳中进行。
