The addition of organometallic reagents to carbonyl compounds has become a versatile method for synthesizing tertiary and secondary alcohols via carbon−carbon bond formation. However, due to the lack of good nucleophilicity or the presence of strong basicity of organometallic reagents, the efficientsynthesis of tertiary alcohols from ketones has been particularly difficult and, thus, limited. We recently
向羰基化合物中添加有机金属试剂已成为通过碳-碳键形成合成叔醇和仲醇的通用方法。然而,由于缺乏良好的亲核性或存在有机金属试剂的强碱性,由酮有效地合成叔醇特别困难并且因此受到限制。我们最近使用ZnCl 2,Me 3 SiCH 2开发了格氏试剂(RMgX:R =烷基,芳基; X = Cl,Br,I),对酮进行了高效的催化烷基化和芳基化反应MgCl和LiCl,可有效减少有问题的副反应。原则上,对于加成羰基化合物,RMgBr和RMgI的反应性不如RMgCl。因此,这种新颖的方法与均相催化的ZnCl 2 ·我3 SICH 2 MgCl·LiCl是相当有吸引力的,因为RMgBr和RMGI,其易于制备和/或可商购的,如RMgCl,可以成功地应用。除酮和醛以外,醛亚胺也有效地用于该催化反应,并以高收率获得了相应的仲胺。关于β-甲硅烷基效应和盐效应的机理细节,原位制备[R(Me 3 SiCH 2)2 Zn] -
Conformational Studies by Dynamic Nuclear Magnetic Resonance. 59.<sup>1</sup> Stereodynamics of Conformational Enantiomers in the Atropisomers of Hindered Naphthylcarbinols
Naphthyldialkylmethanols ArRR'COH (Ar = 1-naphthyl or 1-naphthyl-2-methyl) exist as a pair of atropisomers created by the restricted rotation about the Ar-COH bond. They can be detected by low-temperature NMR spectroscopy but can also be separated as stable compounds at room temperature if both the alkyl substituents are bulky tert-butyl groups (one such example is provided by compound 1, R = R' = Bu(t) with Ar = 1-naphthyl)
Added-Metal-Free Catalytic Nucleophilic Addition of Grignard Reagents to Ketones
作者:Hua Zong、Huayin Huang、Junfeng Liu、Guangling Bian、Ling Song
DOI:10.1021/jo3004277
日期:2012.5.18
reagents to the side of dimeric Grignardreagents to favor the additions of Grignardreagents to ketones via a favored six-membered transition state to form the desired tertiary alcohols, and DGDE should increase the nucleophilic reactivities of Grignardreagents by coordination. This catalytic system has been applied in the efficient synthesis of Citalopram, an effective U.S. FDA-approved antidepressant
Highly Efficient Alkylation to Ketones and Aldimines with Grignard Reagents Catalyzed by Zinc(II) Chloride
作者:Manabu Hatano、Shinji Suzuki、Kazuaki Ishihara
DOI:10.1021/ja0628405
日期:2006.8.1
efficient alkylation to ketones and aldimines with Grignardreagents in the presence of catalytic trialkylzinc(II) ate complexes derived from ZnCl2 (10 mol %) in situ was developed. This simple Zn(II)-catalyzed alkylation could minimize the well-known but serious problems with the use of only Grignardreagents, which leads to reduction and aldol side products, and the yield of desired alkylation products
在由 ZnCl2 (10 mol%) 衍生的催化三烷基锌 (II) 酸酯配合物的存在下,使用格氏试剂高效地烷基化为酮和醛亚胺。这种简单的 Zn(II) 催化烷基化可以最大限度地减少仅使用格氏试剂而导致还原和羟醛副产物的众所周知但严重的问题,并且可以提高所需烷基化产物的产率。
Approach to the synthesis of 1H-2-azaphenalene derivatives
作者:Yu. V. Shklyaev、V. P. Feshin、Yu. V. Nifontov
DOI:10.1134/s1070428009020201
日期:2009.2
By the Hartree-Fock method in the basis 6-31G(d) with complete geometry optimization the charge value on the carbon atom of carbenium ion was shown to be decisive in Ritter reaction with nitriles. It was established that the attack on the peri-position of the naphthalene system to form 1H-2-azaphenalene derivatives was possible only for tetralin derivatives. From the naphthalene only benzo[f]isoquinoline derivatives were formed.