在线看AV的网址,青青青草成人自拍,深喉口爆一区二区三区,5月天黄色视频,精品福利在草草

Hydrogen fluoride-pyridine

0

category
Product
CAS No.
32001-55-1;62778-11-4
Purity
≥99%

Product Details

Name: Hydrogen fluoride-pyridine/PPHF/Pyridine Poly(hydrogen fluoride)/Olah's Reagent

CAS number : 32001-55-1; The 62778-11-4

Molecular formula:C5H5N.nHF(where n≥1)

Purity:≥99%

Appearance: Light yellow to reddish brown transparent liquid

Boiling point: 50℃/1mmHg

Free HF%: 65-70%

Packing: 1kg/ bottle, 25kg/ barrel, 50kg/ barrel

Use: fluorinated reagent

_________________________________________________________________________________________________________

Hydrogen fluoride-pyridine complex (PPHF) is an improvement on the application form and mode of hydrogen fluoride reagent, which can be simply regarded as hydrogen fluoride with a higher boiling point. The PPHF obtained by Olah reagent preparation method can stabilize the temperature of HF emission to about 55 ℃. Compared with anhydrous hydrogen fluoride, PPHF can probably be considered to have the same reaction, the reaction activity is slightly reduced, the selectivity is greatly increased, and the stereochemistry of the product may be different.

PPHF has been widely used in the fluorination ring opening reaction of oxygen - and nitrogen-containing ternary rings. The ring-opening reaction of epoxide fluoridation that can be accomplished by anhydrous hydrogen fluoride can also be accomplished by PPHF [2], and it has been found that PPHF can obtain better results in some reactions [3]. Usually the reaction can be carried out under very mild conditions with very high stereoselectivity and satisfactory yields (Equation 1)[4,5]. The stereochemistry of the fluorinated ring-opening product of the nitrogen-containing ternary ring is just complementary to the anhydrous hydrogen fluoride reagent (Equation 2)[6]

av网址在线导航| 23国模精品在线| 日韩一级特黄AAA| 日韩a级电影在线观看| 伦一理一级一a一片| 色悠久五月| 91视频在线观看导航| 亚洲欧美 都市春色| 国产色色91| 大香蕉国产在线观看| 日韩一级片| 一级A片免费网址| 一级a免费视频2024| 手机免费看黄色A片| 青青草国产| 日韩无码肏屄网| 竹菊影视亚洲精品| 校园AV天堂资源站| 免费黄色3级网络视频| 91看片婬黄大片在看| 日本一区二区在线网站| 黄色Av免费高清亚欧| 在线免费观看av小电影| 亚洲第一毛片| 日韩成人精品| 欧美日韩A片三级片| 欧美亚洲激情| 日韩欧美一级棒电影| 亚洲影视日韩| 日韩视频一本| 中文字幕AV一| av久cao| 大香蕉二级片| 普通一级片| AV 色先锋| 思思热久久AV| 欧美A片资源| 欧美成人久久| 黄色3d视频| 全球av在线观看| 青青草AR|