A silver-catalyzed chlorination of benzylic, tertiary, and secondary C(sp3)–H bonds was developed. The reaction proceeded with as low as 0.2 mol % catalyst loading at room temperature under air atmosphere with synthetically useful functional group compatibility. The regioselectivity and reactivity tendencies suggest that the chlorination proceeded through a radical pathway, but an intermediate alkylsilver
Facile Conversion of Aldehydes and Ketones to <i>gem</i>-Dichlorides Using Chlorodiphenylphosphine/N-Chlorosuccinimide as a New and Neutral System
作者:Ghasem Aghapour、Asieh Afzali
DOI:10.1080/00397910802271271
日期:2008.10.28
Abstract Aldehydes and ketones are easily converted to their corresponding gem-dichlorides using a mixture of chlorodiphenylphosphine and N-chlorosuccinimide (ClPPh2/NCS) in dichloromethane under neutral conditions and at room temperature.
Halogenation through Deoxygenation of Alcohols and Aldehydes
作者:Jia Chen、Jin-Hong Lin、Ji-Chang Xiao
DOI:10.1021/acs.orglett.8b01058
日期:2018.5.18
An efficient reagent system, Ph3P/XCH2CH2X (X = Cl, Br, or I), was very effective for the deoxygenative halogenation (including fluorination) of alcohols (including tertiary alcohols) and aldehydes. The easily available 1,2-dihaloethanes were used as key reagents and halogen sources. The use of (EtO)3P instead of Ph3P could also realize deoxy-halogenation, allowing for a convenient purification process
高效的试剂体系Ph 3 P / XCH 2 CH 2 X(X = Cl,Br或I)对于醇类(包括叔醇)和醛类的脱氧卤化(包括氟化)非常有效。容易获得的1,2-二卤乙烷用作关键试剂和卤素源。使用(ETO)的3 P代替pH为3普还可以实现脱氧卤化,允许方便的纯化方法,作为副产物(ETO)3 P = O可通过水溶液洗涤去除。温和的反应条件,广泛的底物范围和1,2-二卤乙烷的广泛可用性使该方案对卤代化合物的合成具有吸引力。
Synthesis of Vinyl Chlorides via Triphosgene–Pyridine Activation of Ketones
作者:Mirza A. Saputra、Ly Ngo、Rendy Kartika
DOI:10.1021/acs.joc.5b01137
日期:2015.9.4
Herein, we describe a mild method to prepare aliphatic and aromatic vinyl chlorides from their corresponding ketones via triphosgene-pyridine activation in dichloromethane at reflux. The mechanism of this reaction is proposed to involve formation of a putative alpha-chloro pyridinium carbamate intermediate, which appeared to readily undergo E2 elimination in the presence of pyridine.