苯基二氯化膦的合成工艺改进

以PC l3和苯为原料,合成了苯基二氯化膦(1)。用新的配合剂NaC l除去催化剂A lC l3,减少了环境污染,降低了生产成本。在n(苯)∶n(A lC l3)∶n(PC l3)=1.0∶1.1∶3.0,n(NaC l)∶n(A lC l3)=1.6∶1.1,反应时间5 h的最佳反应条件下,1的收率达86.5%。     

无水AlCl3催化合成N-乙基-N-氰乙基苯胺的研究

本文报道了用无水A lC l3作催化剂,催化N-乙基苯胺与丙烯腈反应合成N-乙基-N-氰乙基苯胺的新工艺,优化得到其合适的反应条件是:加入N-乙基苯胺重量的10%的无水A lC l3,在80℃左右反应6-8小时,可使反应的转化率达98.5%,收率达97%以上。     

酸性离子液体催化合成N-氰乙基-N-羟乙基苯胺

N-氰乙基-N-羟乙基苯胺是一种具有广泛用途的染料中间体,针对传统合成方法中的缺陷,以1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO 4)为催化剂,丙烯腈和N-羟乙基苯胺为原料,建立了N-氰乙基-N-羟乙基苯胺的绿色合成新工艺。系统考察了离子液体种类、离子液体用量、底物比例等因素的影响规律,结果表明,[BMIM]HSO 4用量为0.8 mmol,n(N-羟乙基苯胺)∶[KG-*3/5]n(丙烯腈)=1∶[KG-*3/5]1.2,反应温度为90℃,反应时间为12 h时,N-氰乙基-N-羟乙基苯胺产率最高(89%),离子液体循环使用5次后,催化活性基本保持不变。     

微波辐射合成4,4′,4″-三硝基三苯胺

以对硝基苯胺(1)和4-氯硝基苯(2)为原料,二甲基亚砜为溶剂,叔丁醇钾为缚酸剂,氟化钾和四甲基氯化铵为催化剂,在微波辐射下合成了4,4′,4″-三硝基三苯胺(3),其结构经IR表征.正交实验确定最佳反应条件为:13 mmol,n(1)∶n(2)∶n(叔丁醇钾)=1∶3∶2,在125 W下,于130℃反应30 min,3的收率达98.2%.     

4-正丁基-2-硝基苯胺的制备

以对正丁基苯胺为原料,合成了4-正丁基-2-硝基苯胺。经过酰化,硝化,水解三步反应,总收率可达72%。以醋酐为溶剂用浓硝酸硝化,最后用乙醇作溶剂水解得到目标产物。实验得出物料的最佳配比为:n(对正丁基苯胺)∶n(乙酸酐)=1∶3,n(对正丁基乙酰苯胺)∶n(醋酐)∶n(浓硝酸)=1∶3∶5,n(4-正丁基-2-硝基乙酰苯胺)∶n(氢氧化钾)=1∶1.3。     

合成六亚甲基1,6-二氨基甲酸甲酯的新方法

以碳酸二甲酯(DMC)和1,6-己二胺(HDA)为原料合成了六亚甲基1,6-二氨基甲酸甲酯(HDU)。研究了部分Lewis酸对反应的催化活性。其中Zn(NO3)2的催化活性最好。HDA 50 mmol,n(DMC)∶n(HDA)=10∶1,n[Zn(NO3)2]∶n(HDA)=1∶10时,在150℃油浴中回流(90℃)反应3 h,HDU收率可达97%。     

1,3-二甲基金刚烷的合成

以Pd/C为催化剂,于170℃1.5 MPa氢压下还原苊为氢化苊。在A lC l3的催化下,于70℃反应1 h合成了1,3-二甲基金刚烷。总收率66.9%。     

6-硝基喹哪啶的合成工艺改进

以I2/KI为氧化剂,甲苯为乳化剂,对硝基苯胺(2)和巴豆醛(3)经环合反应合成了6-硝基喹哪啶(1)。最佳反应条件为:28.92 mmol,甲苯10 mL,混酸45.5 mL[V(AcOH)∶V(HCl)=1∶90],n(2)∶n(I2/KI)=1∶1,于100℃反应4 h,收率达93.1%。1的结构经1HNMR,IR和元素分析表征。     

O-对甲氧基苯基-N,N-二苄基酪氨酸乙酯的合成

N,N-二苄基酪氨酸乙酯(2)与对溴苯甲醚(3)经偶联反应合成了O-对甲氧基苯基-N,N-二苄基酪氨酸乙酯,其结构经NMR,IR和MS表征。最佳反应条件为:210mmol,n(2)∶n(3)∶n(K3PO4)∶n(CuSO4.5H2O∶n(N,N-二甲基甘氨酸盐酸盐)=1.0∶1.3∶1.3∶0.2∶0.35,在DMF(50mL)中于100℃反应8h,产率54.7%,93.8%ee。     

黑索今的新型合成路线

以乙腈/三聚甲醛为原料合成1,3,5-三乙酰基-均-三嗪（TRAT）,再硝解制备黑索今(RDX)。 聚合反应中,当n(CH3CN)∶n(C3H6O3)=2∶1,n(H2SO4)∶n(C3H6O3)=1∶7.5,反应温度75 ℃,反应3 h时,TRAT的产率为95.2%。 硝解反应中,当n(N2O5)∶n(TRAT)=7∶1,n(HNO3)∶n(N2O5)=6∶1,反应温度45 ℃,反应1 h时,RDX的产率为87.2%。 RDX的全程产率为83.0%。 该工艺简单、易于控制,废酸污染小,有望应用于工业化生产。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.