Nickel-Catalyzed Asymmetric Reductive Cross-Coupling Between Vinyl and Benzyl Electrophiles
作者:Alan H. Cherney、Sarah E. Reisman
DOI:10.1021/ja508067c
日期:2014.10.15
between vinyl bromides and benzyl chlorides has been developed. This method provides direct access to enantioenriched products bearing aryl-substituted tertiary allylic stereogenic centers from simple, stable starting materials. A broad substrate scope is achieved under mild reaction conditions that preclude the pregeneration of organometallic reagents and the regioselectivity issues commonly associated with
已开发出一种 Ni 催化的溴乙烯和苄基氯之间的不对称还原交叉偶联。该方法提供了从简单、稳定的起始材料直接获得带有芳基取代的叔烯丙基立体中心的对映体富集的产品。在温和的反应条件下实现了广泛的底物范围,排除了有机金属试剂的预生成和通常与不对称烯丙基芳基化相关的区域选择性问题。
Visible Light Photocatalysis of [2+2] Styrene Cycloadditions by Energy Transfer
作者:Zhan Lu、Tehshik P. Yoon
DOI:10.1002/anie.201204835
日期:2012.10.8
Hip to be square: Styrenes participate in [2+2] cycloadditions upon irradiation with visible light in the presence of an iridium(III) polypyridyl complex. In contrast to previous reports of visible light photoredox catalysis, the mechanism of this process involves photosensitization by energy transfer and not electron transfer.
bicyclic core structures with up to three stereocenters within a single step. Herein, this concept is combined with the chemistry of chiral Brønsted acid bound ortho-quinonemethideimines to generate a range of interesting fused tetrahydroquinolines in a diastereo- and enantioselective manner.
Kinetically distinct triplets in the photorearrangement of 2-phenylcyclohexanone to cis- and trans-6-phenyl-5-hexenals
作者:Peter J. Wagner、Thomas J. Stratton
DOI:10.1016/s0040-4020(01)92379-8
日期:——
an almost concerted out-of-plane cleavage which forms a 1,6-biradical in the perfect geometry for disproportionation to trans-enal.The precursor to cis-enal may be a minor rotamer of 1 which is forced by nonbonded interactions into a cleavage mode which twists the biradical into a geometry suitable for at least partial formation of cis-enal. In both cases biradicals must be very short-lived and not
Chemoselective and Diastereoselective Intramolecular (3+2) Cycloadditions of Epoxy and Aziridinyl Enolsilanes
作者:Yueyao Chen、Jesse Ling、Angus B. Keto、Yun He、Kam‐Hung Low、Elizabeth H. Krenske、Pauline Chiu
DOI:10.1002/anie.202116099
日期:2022.5.16
Epoxy and aziridinyl enolsilanes react as oxyallylic cation equivalents in diastereoselective intramolecular stepwise (3+2) cycloadditions with acyclic dienes, outcompeting the (4+3) cycloaddition pathway almost exclusively. Computations reveal the factors behind this preference. Optically-enriched trans-hydrindanone cycloadducts can be generated.