查询词典 lewis acid

Alkylamine reaction with dialkyl cyanodithioiminocarbonate was catalyzed by quaternary ammonium salts at room temperature to yield 3-alkylamine-5-amino-1,2,4-triazole in good quality and high yields. After imidization and reaction with an α,β-unsaturated acid derivative, the reaction intermediate was hydrolyzed in the presence of a Lewis acid to obtain the target product.

烷基胺与氰基亚胺硫代二甲酯在季氨盐催化作用下得到质量好、收率高的3-烷氨基-5-氨基-1，2，4-三氮唑，进一步经过亚胺中间体并与α，β-不饱和酸酯作用后，中间产物在Lewis酸催化作用下水解得到三唑嘧啶酮。

Furthermore, the polymerization of benzonitrile catalyzed bydifferent Lewis acid and zinc was also investigated.

测定了以Lewis酸和几种金属催化苯甲腈聚合的反应速度，结果表明金属的活性次序为：镁＞锌＞钠＞钙。

The polymerization rate of benzonitrile catalyzed by Lewis acid and differentmetals was measured, and the activity of metals was in thefollowing decreasing order, magnesium, zinc, sodium, calcium.

发现Lewis酸-金属体系对芳香族腈是一种较好的催化剂，聚合速度比Lewis酸单独催化时有大幅度提高。

This thesis is constituted by four parts: In the first part a summarization is given on the main total synthetic methods of isoflavones, for example, deoxybenzoin method which generally involves two steps wherein a phenol is reacted in the presence of a Lewis acid with phenylacetic acid to generate an intermediate deoxybenzoin which is then cyclized with a one carbon electrophile.

本论文主要工作包括四部分：第一章综述了近年来全合成异黄酮的主要方法：脱氧安息香法，是以多羟基苯酚与苯乙酸或苯乙腈在Lewis酸存在下，反应生成中间体脱氧安息香，然后再与亲电碳试剂进行关环反应生成异黄酮。

The results indicated that new Lewis acid ferric potassium alum was a green catalyst for the synthesis of ethyl lactate.

研究了新型Lewis酸铁钾矾的制备，并以该Lewis酸为催化剂，通过乳酸和乙醇反应合成乳酸乙酯，考察了催化剂用量、反应时间、酸醇物质的量比对酯化率的影响。

The rate enhancement in homogeneous Suzuki reaction by Lewis acid has been investigated.

研究了Lewis酸在Suzuki反应中的促进作用，考察了Lewis酸、溶剂及碱性试剂对目的产物收率的影响，并优化了反应条件。

The role of the oxidant Ce4 in these reactions seemed ambiguous as it could also act as a Lewis acid.

在这个反应中，由于Ce4作为氧化剂的同时又兼具Lewis酸的酸性，因此，在反应的探索过程中，我们一直无法确定到底是Lewis酸催化的离子反应还是电子转移引发的自由基反应接离子反应。

The IR sp ectra of adsorbed pyridine showed that most of the acid sites on the surface of the catalyst are Lewis acid sites.

吸附吡啶的红外光谱证明该催化剂的表面酸点多为Lewis酸点。

There exist Lewis base sites (M=O and M-O-M or M-O-P) and Lewis acid sites on the surface of these catalysts.

催化剂表面的活性基元由Lewis碱位M=O键的端氧和M-O-M或M-O-P键的桥氧位，Lewis酸位M〓组成。

The results showed that there existed Lewis base sites (M=O and M-O-Fe) and Lewis acid sites on the surface of these catalysts.

研究表明，Fe-V-O、Fe-Mo-O、Fe-P-O和Fe-Al-P-O催化剂表面活性基元都是由Lewis碱位（M=O键的端氧和M-O-Fe键的桥氧位）和Lewis酸位组成。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。