α-Halogenation of carbonyl compounds: halotrimethylsilane–nitrate salt couple as an efficient halogenating reagent system
作者:G.K. Sxurya Prakash、Rehana Ismail、Jessica Garcia、Chiradeep Panja、Golam Rasul、Thomas Mathew、George A. Olah
DOI:10.1016/j.tetlet.2011.01.039
日期:2011.3
A mixture of chloro/bromotrimethylsilane and nitrate salt is found to be an effective reagent system for the α-chlorination/bromination of carbonyl compounds. The reaction occurs under mild conditions yielding the products in moderate to good yields.
Switchable Synthesis of α,α‐Dihalomethyl and α,α,α‐Trihalomethyl Ketones by Metal‐Free Decomposition of Enaminone C=C Double Bond
作者:Yunyun Liu、Jin Xiong、Li Wei、Jie‐Ping Wan
DOI:10.1002/adsc.201901234
日期:2020.2.21
(BPO) with mild heating, enabling the tunable synthesis of α,α‐dihalomethyl ketones and α,α,α‐trihalomethyl ketones under different reaction conditions. The formation of these divergent products involving featured C=C double bond cleavage requires no any metal reagent, and represents one more practical example on the synthesis of poly halogenated methyl ketones via the functionalization of carbon−carbon
Solvent-Free Chemoselective Cyanation of α,α-Dibromoacetophenones Using Potassium Hexacyanoferrate(II) as an Eco-Friendly Cyanide Source
作者:Zhouxing Zhao、Zheng Li
DOI:10.1002/ejoc.201000848
日期:——
A chemoselective route for the synthesis of 2-aryl-3,3-di-bromoacrylonitriles by solvent-freecyanation of α,α-dibromoacetophenones by usingpotassiumhexacyanoferrate(II) as an eco-friendlycyanidesource is developed. The merits of this procedure include avoiding the use of a strong toxic cyanidesource, a catalyst, and volatile organic solvents and the high yields of the products.
开发了使用六氰基高铁酸钾 (II) 作为环保氰化物源,通过 α,α-二溴苯乙酮的无溶剂氰化合成 2-芳基-3,3-二溴丙烯腈的化学选择性路线。该程序的优点包括避免使用剧毒的氰化物源、催化剂和挥发性有机溶剂以及产品的高产率。
One-pot furan synthesis through diethylzinc-mediated coupling reaction between two α-bromocarbonyl compounds
作者:Ryo Hikima、Aika Takeshima、Taichi Kano
DOI:10.1039/d3ob01521a
日期:——
Polysubstituted furans were synthesized in one-pot through the Et2Zn-mediated couplingreaction between dibromoketones and monobromo carbonyl compounds and the subsequent β-elimination with bromoacetyl bromide. Polysubstituted pyrroles were also prepared in one-pot by addition of primary amines after the couplingreaction.
An easy and rapid method for the alpha-bromination of ketones using N-bromosuccinimide (NBS) catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time (5-20 min). Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents. (C) 2013 Nallagondu Chinna Gangi Reddy. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.