Cobalt(III)-Catalyzed Functionalization of Unstrained Carbon–Carbon Bonds through β-Carbon Cleavage of Alcohols
摘要:
We demonstrate that a simple Co(III)-complex can efficiently catalyze the cleavage of unstrained C-C bonds via the beta-carbon elimination of secondary and tertiary alcohols bearing a directing group. The cobalt-aryl intermediate generated under the reaction conditions can be trapped by different electrophiles to generate a new carbon carbon bond. Some essential features of this new Co-based mechanistic manifold were revealed by preliminary 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.
Silver catalyzed pyridine‐directed acceptorless dehydrogenation of secondary alcohols
作者:Xin Zhuang、Jing Tao、Zhen Luo、Chuan‐Ming Hong、Zheng‐Qiang Liu、Qing‐Hua Li、Li‐Qing Ren、Qun‐Li Luo、Tang‐Lin Liu
DOI:10.1002/jccs.202000517
日期:2021.2
A silver catalyzed pyridine‐directed acceptorless dehydrogenation of secondary benzyl alcohols was developed. This general procedure delivers ketones with high atom‐economy and hydrogen was the sole byproduct. This dehydrogenation reaction has a good functional group tolerance and high efficiency (up to 90% yield and 10,000/1 substrates‐to‐catalyst ratio).
Dimeric Manganese-Catalyzed Direct Nucleophilic Addition of C(sp<sup>2</sup>)–H Bonds to Inert Aldehydes
作者:Hongxin Liu、Junqin Peng、Bin Li、Baiquan Wang
DOI:10.1021/acs.joc.2c01908
日期:2022.11.4
An efficient direct nucleophilic addition reaction of C(sp2)–H bonds to aldehydes catalyzed by a dimeric manganese has been developed. This reaction has a broad range of substrates, and high yields were also obtained with inert aliphatic aldehydes as substrates. A dimeric Mn2(CO)8Br2 was proven to be a more efficient catalyst precursor than the monomeric Mn(CO)5Br.
Cobalt(III)-Catalyzed Functionalization of Unstrained Carbon–Carbon Bonds through β-Carbon Cleavage of Alcohols
作者:Erhan Ozkal、Bastien Cacherat、Bill Morandi
DOI:10.1021/acscatal.5b01753
日期:2015.11.6
We demonstrate that a simple Co(III)-complex can efficiently catalyze the cleavage of unstrained C-C bonds via the beta-carbon elimination of secondary and tertiary alcohols bearing a directing group. The cobalt-aryl intermediate generated under the reaction conditions can be trapped by different electrophiles to generate a new carbon carbon bond. Some essential features of this new Co-based mechanistic manifold were revealed by preliminary mechanistic studies.
Ruthenium(II)-Catalyzed Grignard-Type Nucleophilic Addition of C(sp<sup>2</sup>)–H Bonds to Unactivated Aldehydes
作者:Lidong Yang、Zezhao Liu、Tingyu Tang、Shibiao Tang、Bin Li、Baiquan Wang
DOI:10.1021/acs.joc.2c02039
日期:2022.11.4
The Grignard-type nucleophilicaddition of C(sp2)–H bonds to aldehydes catalyzed by high-oxidation-state transition metal complexes is limited to activated aldehydes. Herein, we report the first example of Grignard-type nucleophilicaddition of C(sp2)–H bonds to unactivated aldehydes catalyzed by high-oxidation-state ruthenium(II). The reaction has mild reaction conditions and good functional group