1-Ethyl 2-Halopyridinium Salts, Highly Efficient Coupling Reagents for Hindered Peptide Synthesis both in Solution and the Solid-Phase
作者:Peng Li、Jie-Cheng Xu
DOI:10.1016/s0040-4020(00)00657-8
日期:2000.10
proved to be very effective for the synthesis of hindered peptides containing N-methylated or Cα,Cα-dialkylated amino acid residues. HPLC monitoring of model reactions indicated that these pyridinium salts demonstrated higher reactivities, lower racemization than the commonly used halogenated uronium and phosphonium salts. The efficiency of these pyridinium type coupling reagents was further proved by the
1-乙基-2-卤代吡啶鎓盐,BEP,FEP,BEPH和FEPH,合成并证明是含有受阻的肽的合成是非常有效的Ñ甲基化的或Ç α,Ç α-二烷基化的氨基酸残基。HPLC对模型反应的监测表明,与通常使用的卤化铀盐和phospho盐相比,这些吡啶鎓盐具有更高的反应活性和更低的消旋性。通过合成一系列受阻的寡肽和活性酯,具有良好的收率和方便的后处理,进一步证明了这些吡啶鎓类偶联剂的效率。使用这些吡啶鎓盐还成功合成了环孢菌素A(CsA)的8-11四肽片段和Dolastatin 15的五肽部分。这些吡啶鎓类偶联剂对SPPS的效率还通过CsA的极受阻碍的8-11肽段和CsO的线性十一肽的固相合成证明。1 H NMR,IR和HPLC。提出主要的反应性中间体是N-保护的氨基酸或肽的相应的酰卤和酰氧基吡啶鎓盐。
Homoleptic Cobalt and Copper Phenolate A<sub>2</sub>[M(OAr)<sub>4</sub>] Compounds: The Effect of Phenoxide Fluorination
作者:Marisa C. Buzzeo、Amber H. Iqbal、Charli M. Long、David Millar、Sonal Patel、Matthew A. Pellow、Sahar A. Saddoughi、Abigail L. Smenton、John F. C. Turner、Jay D. Wadhawan、Richard G. Compton、James A. Golen、Arnold L. Rheingold、Linda H. Doerrer
DOI:10.1021/ic0493954
日期:2004.11.1
dramatic structural changes effected by modification of OPh to OAr(F). The compounds [K(18-crown-6)]2[Cu(OArF)4], 1a; [K(18-crown-6)]2[Cu(OAr')4], 1b; [Tl2Cu(OArF)4], 2a; [Tl2Cu(OAr')4], 2b; (Ph4P)2[Cu(OArF)4], 3; (nBu4N)2[Cu(OArF)4], 4; (HEt3N)2[Cu(OArF)4], 5; [K(18-crown-6)]2[Cu2(mu2-OC6H5)2(OC6H5)4], 6; [K(18-crown-6)]2[Co(OArF)4], 7a; [(18-crown-6)]2[Co(OAr')4], 7b; [Tl2Co(OArF)4], 8a; [Tl2Co(OAr')4],
Living Polymerization of (<i>o</i>-(Trimethylsilyl)phenyl)acetylene by Molybdenum Imido Alkylidene Complexes
作者:Richard R. Schrock、Shifang Luo、Jesse C. Lee、Nadia C. Zanetti、William M. Davis
DOI:10.1021/ja954155w
日期:1996.4.24
4-lutidine occupies an axial position, a structure that results from addition of 2,4-lutidine to the CNO face of unstable pseudotetrahedral syn-Mo(CHCMe2Ph)(NAd)[OCH(CF3)2]2. 2a reacts with (o-(trimethylsilyl)phenyl)acetylene (o-TMSPA) solely via formation of an α-substituted metallacyclobutene intermediate (α addition) that opens to give a single rotamer of a disubstituted alkylidene complex. o-TMSPA is smoothly
Synthesis with Structural and Electronic Characterization of Homoleptic Fe(II)- and Fe(III)-Fluorinated Phenolate Complexes
作者:Stefanie A. Cantalupo、Helen E. Ferreira、Eman Bataineh、Annie J. King、Montana V. Petersen、Teresa Wojtasiewicz、Antonio G. DiPasquale、Arnold L. Rheingold、Linda H. Doerrer
DOI:10.1021/ic2003782
日期:2011.7.18
Four Fe(III) compounds and one Fe(II) compound containing mononuclear, homoleptic, fluorinated phenolate anions of the form [Fe(OAr)m]n− have been prepared in which ArF = C6F5 and Ar′ = 3,5-C6(CF3)2H3: (Ph4P)2[Fe(OArF)5], 1, (Me4N)2[Fe(OArF)5], 2, K(18-crown-6)}2[Fe(OArF)5], 3a, K(18-crown-6)}2[Fe(OAr′)5], 3b, and K(18-crown-6)}2[Fe(OArF)4], 6. Two dinuclear Fe(III) compounds have also been prepared:
New and Highly Efficient Immonium Type Peptide Coupling Reagents: Synthesis, Mechanism and Application
作者:Peng Li、Jie-Cheng Xu
DOI:10.1016/s0040-4020(00)00365-3
日期:2000.6
A series of novel immonium type couplingreagents BOMI, BDMP, BPMP, DOMP, SOMP, FOMP and AOMP were designed and synthesized. It was shown that most of these reagents were more efficient in peptide synthesis than conventional methods due to the advantages of high reactivity, low racemization and good yields. The reaction mechanism was proposed and studied by 1H NMR, IR, UV and HPLC.
设计合成了一系列新型的铵型偶联剂BOMI,BDMP,BPMP,DOMP,SOMP,FOMP和AOMP。结果表明,由于具有高反应活性,低外消旋性和高收率的优势,大多数这些试剂在肽合成方面比常规方法更有效。提出了反应机理,并通过1 H NMR,IR,UV和HPLC进行了研究。