Palladium-Catalyzed Stereospecific Decarboxylative Benzylation of Alkynes
摘要:
Enantioenriched benzyl esters of propiolic acids undergo highly stereospecific decarboxylative coupling to provide 1,1-diarylethynyl methanes. This sp-sp(3) coupling does not require strongly basic conditions or preformed organometallics and produces CO2 as the sole byproduct. Ultimately, this method results in the successful transfer of stereochemical information from secondary benzyl alcohols to generate enantioenriched tertiary diarylmethanes.
AlCl<sub>3</sub>and BDMAEE: A Pair of Potent Reactive Regulators of Aryl Grignard Reagents and Highly Catalytic Asymmetric Arylation of Aldehydes
作者:Xin-Yuan Fan、Yong-Xin Yang、Fang-Fang Zhuo、Sheng-Li Yu、Xiao Li、Qi-Peng Guo、Zhi-Xue Du、Chao-Shan Da
DOI:10.1002/chem.201000974
日期:2010.7.19
Cheap, energy‐saving, and applicable: With the aid of AlCl3 and BDMAEE [2,2′‐oxybis(N,N‐dimethylethanamine)], a highly asymmetriccatalytic addition of various aryl Grignard reagents to aldehydes was achieved under mild conditions with easily prepared (S)‐H8‐BINOL and inexpensive commercially available Ti(OiPr)4 (see scheme), and the reaction could be easily scaled up with no loss of yield and enantioselectivity
廉价,节能且适用:借助AlCl 3和BDMAEE [2,2'-氧双(N,N-二甲基乙胺)],在温和条件下,将各种芳基格氏试剂高度不对称催化加成到醛中用易于制备的(S)-H 8 -BINOL和便宜的市售Ti(O i Pr)4(参见方案),该反应可以轻松扩大规模,而不会损失收率和对映选择性。
The inexpensive additive <i>N</i>
-methylmorpholine effectively decreases the equivalents of nucleophiles in the catalytic highly enantioselective arylation of aryl aldehydes
作者:Pei Wang、Yue Liu、Ya-Lun Zhang、Chao-Shan Da
DOI:10.1002/chir.22709
日期:2017.8
Highlyenantioselectivearylation of arylaldehydes catalyzed by (S)‐H8‐BINOL‐Ti(Oi‐Pr)2 complex in the presence of N‐methylmorpholine (NMM) as an effective and inexpensiveadditive is described for the first time. We found high enantioselectivity and yield but successfully reduced the equivalents of nucleophiles triarylaluminums by 50% compared with our previous report. The practicability of the process
首次描述了在有效的,廉价的N-甲基吗啉存在下,由(S)-H 8 -BINOL-Ti(O i - Pr)2络合物催化的芳醛的高度对映选择性芳基化反应。我们发现对映选择性和产率很高,但与我们以前的报告相比,亲核试剂三芳基铝的当量成功降低了50%。由此大大提高了该方法的实用性。
Synthesis of new benzimidazolium salts and their application in the asymmetric arylation of aldehydes
作者:Wei-Ping He、Bi-Hui Zhou、Ya-Li Zhou、Xiang-Rong Li、Li-Mei Fan、Hao-Wen Shou、Jie Li
DOI:10.1016/j.tetlet.2016.06.023
日期:2016.7
precursor of N-heterocyclic carbene ligands, were designed and synthesized from 1,2-dibromobenzene. In situ prepared corresponding carbenes were tested in asymmetric Rh-catalyzed arylation of aromatic aldehydes, affording chiral diarylmethanols with high yields and moderate enantioselectivities.
Photoassisted Cobalt-Catalyzed Asymmetric Reductive Grignard-Type Addition of Aryl Iodides
作者:Xuan Jiang、Hao Jiang、Qian Yang、Ying Cheng、Liang-Qiu Lu、Jon A. Tunge、Wen-Jing Xiao
DOI:10.1021/jacs.2c02481
日期:2022.5.11
Grignard addition is one of the most important methods used for syntheses of alcohol compounds and has been known for over a hundred years. However, research on asymmetric catalysis relies on the use of organometallic nucleophiles. Here, we report the first visible-light-induced cobalt-catalyzed asymmetric reductive Grignard-type addition for synthesizing chiral benzyl alcohols (>50 examples, up to