A convenient one-step transformation of primary and secondary amines into the corresponding unprotected guanidines using 4-benzyl-3,5-dimethyl-1H-pyrazole-1-carboxamidine and its polymer-bound variant is described. The scopes and limitations of the method, the microwave-assistance of amidination as well as a recycling protocol are examined.
Syntheses of 4-benzyl-3,5-dimethylpyrazolylborato complexes of molybdenum and tungsten nitrosyls: molecular structure of [Mo(CO)<sub>2</sub>(NO){HB(3,5-Me<sub>2</sub>-4-PhCH<sub>2</sub>C<sub>3</sub>N<sub>2</sub>)<sub>3</sub>}], a complex with an ‘inverted’ bowl-like structure
作者:John C. Jeffery、Stefan S. Kurek、Jon A. McCleverty、Elefteria Psillakis、Rob M. Richardson、Michael D. Ward、Andrzej Wlodarczyk
DOI:10.1039/dt9940002559
日期:——
effect in the new species. However, a crystal and molecularstructure determination of [Mo(CO)2(NO)HB(bdmpz)3}] revealed that the molecule has a highly symmetrical structure, the CH2groups of the benzyl groups in the tris(pyrazolyl)borate ligand being disposed in a star-shaped configuration where the phenylrings adopt an ‘inverted’ bowl-like structure with the BH group inside and the Mo(CO)2(NO) group
[HB(bdmpz)3 ] –的反应,是通过4-苄基-3,5-二甲基吡唑(Hbdmpz)与KBH 4的反应,与[M(CO)6 ](M = Mo或W)和p -MeC 6 H 4 SO 2 N(NO)Me提供[M(CO)2(NO)-HB(bdmpz)3 }](M = Mo或W)。羰基钼被转化为[Mo(NO)-HB(bdmpz)3 } X(Y)](X = Y = Cl,I或OC 6 H 4 Me- p; X = Cl,Y = OMe或OC 6 ħ 4 ME- p)的光谱和电化学性质与[Mo(NO)HB(dmpz)3 } X(Y)](Hdmpz = 3,5-二甲基吡唑)几乎相同,表明苄基的添加具有在新物种中没有明显的电子效应。然而,[Mo(CO)2(NO)HB(bdmpz)3 }]的晶体和分子结构测定表明该分子具有高度对称的结构,即三(吡唑基)中苄基的CH 2基团。硼酸盐配体以星形构型排列
Migration tendencies of functional groups toward sigmatropic rearrangement in 3,3-disubstituted 3H-pyrazoles
作者:Peter Sciess、Henri Stalder
DOI:10.1016/s0040-4039(00)92734-5
日期:——
3,3-Disubstituted 3H-pyrazoles - aromatise through an intramolecular sigmatropic 1,5-(1,2-) shift of one of the quaternary groups. From a kinetic study of the uncatalysed and of the acidcatalysed isomerisation reaction migration tendencies of functional groups in sigmatropic rearrangement toward neutral and toward cationic centers are obtained.
Syntheses, Crystal Structures and Luminescent Properties of a Dimeric Complex [(bzdmpzm)Cu(µ-I)]2 and a Polymeric Complex [(bzdmpzm)Cu(µ-NCS)]n (bzdmpzm=Bis(4-benzyl-3,5-dimethyl-1H-pyrazol-1-yl)methane)
作者:Huihui Wang、Hongxi Li、Zhigang Ren、Yang Chen、Jianping Lang
DOI:10.1002/cjoc.201090235
日期:——
(X=I, NCS) with bis(4‐benzyl‐3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane (bzdmpzm) in MeCN resulted in the formation of one dimer [(bzdmpzm)Cu(µ‐I)]2 (1) and one 1D polymer [(bzdmpzm)Cu(µ‐NCS)]n (2) in high yields. 1 and 2 were characterized by elemental analysis, IR, 1H NMR spectra, powder X‐ray diffraction and single‐crystal X‐ray diffraction. 1 consists of two scorpion‐like [(bzdmpzm)Cu]+ fragments bridged