An allylation reaction was explored for the synthesis of ethyl α-methylene-γ-amino carboxylates by treating aldehydes, aryl amines and ethyl 2-(bromomethyl)acrylate with tin powder at room temperature in 1,4-dioxane. The method is highly efficient and environmentally benign with catalyst-free, low cost and concise manipulation. Keywords tin powder; aldehydes; amines; ethyl α-methylene-γ-amino carboxylates; allylation

An one-pot reaction was developed for the synthesis of homoallylhydrazides by treating aldehydes, aryl acylhydrazines and allyl bromide with tin powder at room temperature in tetrahydrofuran. The reaction proceeded smoothly without using any catalyst under mild conditions to give the corresponding products in high yields.

An asymmetric Henry reaction with 2,2,2-trifluoroacetophenone as trifluoromethyl building block was described. This reaction was catalyzed by bifunctional thiourea derived from quinine to give the product bearing a CF 3 stereogenic center in good yield with good enantioselectivity.

An one-pot reaction of glyoxylate ethyl ester, acylhydrazines and allyl bromide promoted by tin powder has been developed. The reaction has been investigated using different acylhydrazines leading to allylic α-acylhydrazino esters in very high yield. When allyl bromide was replaced with prenyl bromide or crotyl bromide to perform the reaction, the γ-addition products were obtained. The reaction provides a new approach for the synthesis of allylic α-acylhydrazino esters. Keywords tin powder; glyoxylate ethyl ester; acylhydrazines; one pot reaction; allylic α-acylhydrazino esters 不饱和氨基酸是一类天然存在的具有许多生物活 性的物质 [1]. 其中, γ,δ-不饱和氨基酸特别受到人们的广 泛关注. 因为这类化合物是非常重要的蛋白氨基酸, 常 常作为合成复杂氨基酸和肽的前体 [2] , 并且已从天然植 物和微生物体内分离得到 [3]. 由于其分子中的碳碳双键 很容易通过化学过程转变为其他官能团, 因此 γ,δ-不饱 和氨基酸也是有机合成中非常重要的合成砌块, 在模拟 肽药物发现等方面具有重要应用 [4～6]. 目前, 不饱和氨 基酸的合成, 特别是具有光学活性的不饱和氨基酸的合 成方法已有很多. 常见的方法主要有: 以氨基酸的阳离 子 [7] 、阴离子 [8] 或自由基 [9] 的等价物为原料的合成, 通过 重排反应 [10] 、 复分解反应 [11] 和 Witting 反应 [5,12] 等进行合 成．在这些众多的合成方法中, 乙醛酸酯的亚胺或其类 似物和烯丙基金属试剂的亲核加成是获得不饱和氨基 酸及其衍生物的一种最直接方法 [2a,13] .

A series of trifluoromethylated homoallylic N-acylhydrazines were obtained from one-pot reaction of aryl trifluoroketones, acylhydrazines and allyl bromide promoted by tin powder in the presence of boron trifluoride diethyl etherate (BF 3 •OEt 2 ). The features of this process include good yields, wide substrate scope, mild conditions and easy operation. Trifluoromethylated homoallylic N-acylhydrazines are useful trifluoromethyl building blocks. They can be easily transformed into trifluoromethylated nitrogen-containing compounds. Keywords one-pot; tin powder; aryl trifluoroketones; trifluoromethylated homoallylic N-acylhydrazines 近年来, 有机氟化学得到了迅速的发展, 其中含三 氟甲基的有机化合物在医药 [1] 、农药 [2] 、染色工业及材 料科学 [3] 等诸多领域得到了广泛的应用, 备受化学家关 注, 发展了各种有效的方法合成含三氟甲基的有机化合 物. 三氟甲基合成砌块法合成含三氟甲基的有机化合物 是一种简便有效的方法 [4] . 含三氟甲基合成砌块法主要 是利用含氟砌块上原有的官能团的转化从而合成结构 复杂的含氟有机化合物. 芳基三氟甲基酮是一类重要的 亲电含氟有机合成砌块, 可以发生还原反应 [5] 、1,2-加成 反应 [6] 、 Crossed-Tishchenko 反应 [7] 、 Aldol 反应 [8] 、 Micheal 加成 [9] 反应及 Henry 反应 [10] , 简单高效地转化为一系列 重要的三氟甲基有机化合物. 高烯丙基酰肼类化合物是一类有用的有机合成中 间体, 可简单高效地转化为高烯丙基胺 [11] 和吡唑及其它 含氮衍生物 [12] . 高烯丙基酰肼一般可由酰腙类化合物 与烯丙基化试剂( 例如有机锡 [13] 、有机铟 [14] 及有机 硅 [11b,15] 等)反应制备, 也可由酰腙类化合物与烯丙基卤 在锡粉 [16] 或铟粉 [17] 促进下反应制备. 本文报道在锡粉 促进下, 以芳基三氟甲基酮为三氟甲基合成砌块, 与酰 肼、烯丙基溴"一锅法"反应制备含三氟甲基的高烯丙 基酰肼化合物, 为三氟甲基高烯丙基酰肼类化合物的合 成提供了一种简便高效的方法, 三氟甲基高烯丙基酰肼 可方便地转化为三氟甲基高烯丙基胺. 1 结果与讨论 1.1 反应条件的优化 首先我们以对甲苯磺酸(TsOH)为促进剂, 四氢呋喃 (THF)为溶剂, 将 2,2,2-三氟苯乙酮(1a)、苯甲酰肼(2a)、