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排序方式: 共有261条查询结果,搜索用时 15 毫秒
1.
2.
General indole C3 reductive alkylation conditions have been developed. The scope of this reaction includes C2 unsubstituted indoles, aryl and alkyl aldehydes, as well as N-H and N-alkyl indole substrates. 相似文献
3.
Yinghong Sheng Jerzy Leszczynski Thuc-Quyen Nguyen Anu Bamgbelu 《Structural chemistry》2007,18(6):827-832
A theoretical study using density functional theory was performed to understand the structure/property relationship of the
cationic conjugated polyelectrolytes, poly[9,9-bis-(6′-N,N,N-trimethylammonium) hexyl] fluorene-alt-4,7-(2,1,3-benzothiadiazole)] (PFBT-X, where X = Br). The torsion angle between the fluorene and benzothiadiazole units in the PFBT monomer was found to substantially affect
the structural and electronic properties of the cationic PFBT monomer. The changes of geometrical parameter, HOMO and LUMO energy levels, and band gap, as well as the absorption maximum
are discussed in terms of the torsion in the PFBT monomer structure. For comparison, its neutral analogue, the monomer of
poly(9,9-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) was also studied. The length of conjugation backbone was also examined. 相似文献
4.
Ajay K. Bose Subhendu N. Ganguly Maghar S. Manhas Vaidyanathan Srirajan Ashoke Bhattacharjee Sochanchingwung Rumthao Anju H. Sharma 《Tetrahedron letters》2004,45(6):1179-1181
A novel dinitro secondary metabolite, 2-nitro-4-(2′-nitroethenyl)phenol from a marine source, has been prepared via highly accelerated, microwave assisted, nitration reactions using mild reagents. ipso-Substitution of a carboxy group by a nitro group is discussed. 相似文献
5.
Ghosh S Krishnan A Das PK Ramakrishnan S 《Journal of the American Chemical Society》2003,125(6):1602-1606
The critical micelle concentration (CMC) of several surfactants that contain an NLO chromophore, either at the hydrocarbon tail, or at the hydrophilic headgroup, or even as a counterion, was determined by hyper-Rayleigh scattering (HRS). In all cases, the HRS signal exhibited a similar variation with surfactant concentration, wherein the CMC is inferred from a rather unprecedented drop in the signal intensity. This drop is attributed to the formation of small pre-micellar aggregates, whose concentrations become negligible above CMC. In addition, a probe molecule, which upon protonation yielded a species with significantly enhanced HRS intensity, was developed and its utility for the determination of the CMC of simple fatty acids was demonstrated. 相似文献
6.
Gaucher disease-associated glucocerebrosidases show mutation-dependent chemical chaperoning profiles
Sawkar AR Adamski-Werner SL Cheng WC Wong CH Beutler E Zimmer KP Kelly JW 《Chemistry & biology》2005,12(11):1235-1244
Gaucher disease is a lysosomal storage disorder caused by deficient glucocerebrosidase activity. We have previously shown that the cellular activity of the most common Gaucher disease-associated glucocerebrosidase variant, N370S, is increased when patient-derived cells are cultured with the chemical chaperone N-nonyl-deoxynojirimycin. Chemical chaperones stabilize proteins against misfolding, enabling their trafficking from the endoplasmic reticulum. Herein, the generality of this therapeutic strategy is evaluated with other glucocerebrosidase variants and with additional candidate chemical chaperones. Improved chemical chaperones are identified for N370S glucocerebrosidase. Moreover, we demonstrate that G202R, a glucocerebrosidase variant that is known to be retained in the endoplasmic reticulum, is also amenable to chemical chaperoning. The L444P variant is not chaperoned by any of the active site-directed molecules tested, likely because this mutation destabilizes a domain distinct from the catalytic domain. 相似文献
7.
Ajay K. Bose Maghar S. Manhas Suhas Pednekar Subhendu N. Ganguly Hoang Dang William He Arun Mandadi 《Tetrahedron letters》2005,46(11):1901-1903
An important stage in process development is kilo scale preparation of the target compound. For this reason, a procedure involving water-based biphasic reaction media has been developed for conducting some exothermic reactions on a large scale. This protocol is illustrated by the energy-efficient and rapid preparation of dihydropyrimidinones by a solvent-free, green chemistry procedure applied to the Biginelli reaction using p-toluenesulfonic acid as catalyst. 相似文献
8.
9.
Baldev Singh Manhas Narinder Kaur Ajaib Singh Dhindsa 《Transition Metal Chemistry》1992,17(4):287-291
New copper(II) acetate complexes with the saturated diheterocyclic bases (L-L): piperazine, 1-methylpiperazine, and 1,4-dimethylpiperazine
and their monohydrochlorides, have been prepared and characterised by physico-chemical and spectroscopic methods. They are
magnetically dilute and antiferromagnetic, with stoichiometries of the type Cu(OAc)2(B)n(B=L-L or L-LHCl and n=2, 1 or 0.5). 相似文献
10.
Reaction of dienamine 4a with substituted phenacyl bromides gave steroidal[3,4-b] furans 5a–g. The same principle reaction was utilized for the total synthesis of (±) 2 - (p - chlorophenyl) - 3 - oxa - A - nor - estra - 1,5(10), 9(11) - triene - 17 - acetate 12a. Treatment of 4a, b with benzenediazonium salts, in DMF, followed by a Fischer-indole cyclization yielded steroidal[6, 7-b] indoles 8a–k. Dienamine 4b could be annelated to benz[4, 5, 6] steroids 9a and 9b by reaction with methyl vinyl ketone and crotonaldehyde, respectively. 相似文献