Manganese-Catalyzed Direct Nucleophilic C(sp<sup>2</sup>)H Addition to Aldehydes and Nitriles
作者:Bingwei Zhou、Yuanyuan Hu、Congyang Wang
DOI:10.1002/anie.201506187
日期:2015.11.9
Herein, a manganese‐catalyzed nucleophilicaddition of inert C(sp2)H bonds to aldehydes and nitriles is disclosed by virtue of a dual activation strategy. The reactions feature mild reaction conditions, excellent regio‐ and stereoselectivity, and a wide substrate scope, which includes both aromatic and olefinic CH bonds, as well as a large variety of aldehydes and nitriles. Moreover, mechanistic studies
Reductive Cleavage of the C sp 2C sp 3 Bond of Secondary Benzyl Alcohols: Rhodium Catalysis Directed by N-Containing Groups
作者:Kang Chen、Hu Li、Zhi-Quan Lei、Yang Li、Wen-He Ye、Li-Sheng Zhang、Jian Sun、Zhang-Jie Shi
DOI:10.1002/anie.201204338
日期:2012.9.24
1,1‐Biarylmethanol substrates undergo reductivecleavage of the CCbond in the presence of a cationic RhIII catalyst and H2 (see scheme; DG=directinggroup). Various functional groups are tolerated in the reaction system. Preliminary studies indicate that a five‐membered rhodacycle intermediate, which then converts into a RhIII hydride species for the reduction, is involved in the catalytic cycle.
Pyridinyl Directed Alkenylation with Olefins via Rh(III)-Catalyzed C–C Bond Cleavage of Secondary Arylmethanols
作者:Hu Li、Yang Li、Xi-Sha Zhang、Kang Chen、Xin Wang、Zhang-Jie Shi
DOI:10.1021/ja205228y
日期:2011.10.5
Novel C-C bondcleavage of secondary alcohols through Rh(III)-catalyzed β-carbon elimination directed by a pyridinyl group is reported. A five-membered rhodacycle is proposed as a key intermediate, which undergoes further alkenylation with various olefins. This novel transformation shows high efficiency along with excellent selectivity in mild conditions. A wide range of functionalities are compatible
报道了仲醇通过由吡啶基团引导的 Rh(III) 催化的 β-碳消除来裂解仲醇的新型 CC 键。五元罗达环被提议作为关键中间体,它与各种烯烃进行进一步的烯基化。这种新型转化在温和条件下显示出高效率和出色的选择性。兼容多种功能。本研究提供了一种新的策略来进行 CC 键活化。
Extrusion of CO from Aryl Ketones: Rhodium(I)-Catalyzed CC Bond Cleavage Directed by a Pyridine Group
作者:Zhi-Quan Lei、Hu Li、Yang Li、Xi-Sha Zhang、Kang Chen、Xin Wang、Jian Sun、Zhang-Jie Shi
DOI:10.1002/anie.201107136
日期:2012.3.12
The rhodium(I)‐catalyzed extrusion of carbon monoxide from biaryl ketones and alkyl/alkenyl arylketones was developed to produce biaryls and alkyl/alkenyl arenes, respectively, in high yields (see scheme). A wide range of functionalities are tolerated. Not only does this method provide an alternative pathway to construct useful scaffolds, but also offers a new strategy for CCbond activation.
Electro-Oxidative C–C Alkenylation by Rhodium(III) Catalysis
作者:Youai Qiu、Alexej Scheremetjew、Lutz Ackermann
DOI:10.1021/jacs.8b13692
日期:2019.2.13
C-C activations were accomplished by expedient oxidative rhodium(III) catalysis. Thus, oxidative C-C alkenylations proved viable with the aid of electricity, avoiding the use of toxic and/or expensive transition-metal oxidants. The chelation-assisted C-C functionalizations proceeded with ample scope and excellent levels of chemo- and position selectivities within an organometallic C-C activation manifold
电化学 CC 活化是通过方便的氧化铑 (III) 催化完成的。因此,氧化性 CC 烯基化证明在电的帮助下是可行的,避免使用有毒和/或昂贵的过渡金属氧化剂。螯合辅助的 CC 功能化在有机金属 CC 活化歧管内以广泛的范围和优异的化学和位置选择性进行。详细的机理研究为动力学相关的 CC 断裂提供了支持,并且明确定义的有机金属铑 (III) 配合物被确定为具有催化能力的中间体。电化学 CC 功能化不需要额外的电解质,可以在克规模上进行,并提供对密集的 1,2,3-取代芳烃的位置选择性访问,这些芳烃不能通过 CH 活化。