洞察安全,简单且廉价的磷酸(H 3 PO 4描述了醇用酸酐的)催化的酰化。与传统上提出的单酰化混合酸酐不同,提出了相应的原位生成的二酰化混合酸酐作为活性物质。特别地,二酰基化的混合酸酐充当有效的催化酰基转移试剂,而不是充当简单活化酸酐的布朗斯台德酸催化剂。值得注意的是,实现了高效磷酸(1-3 mol%)催化的醇与酸酐的酰化作用,并证明了23 g规模的酯的合成。另外,磷酸催化剂对于从羧酸,醇和酸酐的合成有用的酯化是有效的。此外,关于手性1的最新发展,1'-联-2-萘酚(BINOL)衍生的磷酸二酯催化剂通过酰化作用对醇的不对称动力学拆分,研究了一些磷酸二酯。结果,31 P NMR研究和动力学研究不仅大力支持了其他研究人员先前提出的酸碱协同机理,而且也大力支持了我们目前提出的混合酸酐机理。
SALT, RESIN, RESIST COMPOSITION AND METHOD FOR PRODUCING RESIST PATTERN
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:US20160052877A1
公开(公告)日:2016-02-25
A salt represented by the formula (I);
wherein Q
1
and Q
2
each independently represent a fluorine atom or a C
1
to C
6
perfluoroalkyl group, L
b1
represents a single bond or a divalent C
1
to C
24
saturated hydrocarbon groupwhere a methylene group may be replaced by an oxygen atom or a carbonyl group and where a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom, and Y represents a hydrogen atom, a fluorine atom, or an optionally substituted C
3
to C
18
alicyclic hydrocarbon groupwhere a methylene group may be replaced by an oxygen atom, a carbonyl group or a sulfonyl group; and Ar represents a divalent C
6
to C
20
aromatic hydrocarbon group, and Z
+
represents an organic sulfonium cation or an organic iodonium cation.
Hafnium inspired activation of highly hindered anhydrides in the acylation of alcohols and polyols
作者:Enoch Mensah、Aaron Day、Raven Thomas
DOI:10.1016/j.tetlet.2018.02.009
日期:2018.3
A novel and highlyefficient method for activating highly hindered acid anhydrides towards the acylation of alcohols and carbohydrate-derived polyols has been developed. This new method relies on the capacity of the hafnium triflate catalyst Hf(OTf)2 to activate highly hindered acid anhydrides, and to direct the acylation reaction. This new acylation protocol is mild and proceed at room temperature
TRIAZOLYL ACYCLIC HEPATITIS C SERINE PROTEASE INHIBITORS
申请人:Sun Ying
公开号:US20080038225A1
公开(公告)日:2008-02-14
The present invention relates to compounds of Formula I or II, or pharmaceutically acceptable salts, esters or prodrugs thereof:
which inhibit serine protease activity, particularly the activity of hepatitis C virus (HCV) NS3-NS4A protease. Consequently, the compounds of the present invention interfere with the life cycle of the hepatitis C virus and are also useful as antiviral agents. The present invention further relates to pharmaceutical compositions comprising the aforementioned compounds for administration to a subject suffering from HCV infection. The invention also relates to methods of treating an HCV infection in a subject by administering to the subject a pharmaceutical composition comprising a compound of the present invention.
Engineering Reactions in Crystalline Solids: Radical Pairs in Crystals of Dialkyl 1,3-Acetonedicarboxylates
作者:Zhe Yang、Miguel A. Garcia-Garibay
DOI:10.1021/ol006042+
日期:2000.6.1
dialkyl succinates in high chemical yields by combination of alpha-carbonyl radicalpairs produced by photochemical decarbonylation. It is proposed that the solid-state reaction depends on the exothermicity of two consecutive bond cleavage processes. It is also suggested that the efficiency of radical formation in the solid state is determined by the effect of substituents on bond dissociation energies
Engineering Reactions in Crystalline Solids: Photochemical Generation of Secondary and Tertiary Enol Radical Pairs from Crystalline Ketodiesters
作者:Zhe Yang、Danny Ng、Miguel A. Garcia-Garibay
DOI:10.1021/jo005747m
日期:2001.6.1
solution and in the solid state. It is shown that the efficiency of the solid-state reaction depends on the stability of the intermediate acyl-alkyl and alkyl-alkyl radicalpairs. Reactions proceeding through tertiary enol radicals are more efficient than reactions proceeding through secondary enol radical centers. Solid-state reactions that require the intermediacy of primary enol radicals do not occur.