[Bis(dicyclohexylphosphino)ethane]platinum(0). Reactions with alkyl, (trimethylsilyl)methyl, aryl, benzyl, and alkynyl carbon-hydrogen bonds
作者:Marifaith. Hackett、George M. Whitesides
DOI:10.1021/ja00213a016
日期:1988.3
prepare l'intermediaire du titre qui reagit aussitot avec des composes aliphatiques, alicycliques, des composes benzeniques pour donner soit des complexes mixtes, soit des complexes d'alkyl, cyclanyl ou aryl platine
A partir du complexe 通讯员 de neopentyl platine on prepare l'intermediaire du titre qui reagit aussitot avec des composes aliphatiques, alicycliques, des composes benzeniques pour donner soit des complexes mixtes, soit des complexes d'alkyl, cyclanyl ou aryl platine
Thermolytic reactions of esters. Part 12. Steric versus polar effects in pyrolytic β-elimination of acetic acid from (tertiary) alkyl acetates
作者:Robert Louw、Hans P. W. Vermeeren、Martijn W. Vogelzang
DOI:10.1039/p29830001875
日期:——
The vapour-phase pyrolysis of the crowded tertiaryalkyl acetates AcOCMe2But(II) and AcOCMePri2(III) to give aceticacid and the appropriate alkene(s) has been studied. Rates of formation of alk-1-ene and of isobutene from t-butyl acetate were compared. On this basis steric acceleration in pyrolysis of AcOR, employing known steric parameters E′s from groups R, is quantitatively analysed. Although the
的气相热解拥挤叔烷基乙酸酯AcOCMe 2卜吨(II)和AcOCMePr我2(III),得到乙酸和适当的烯烃(一个或多个)已被研究。比较了由乙酸叔丁酯形成烷-1-烯和异丁烯的速率。在ACOR的热解此基础上的空间位加速度,采用公知的位阻参数ë '小号从基团R,进行定量分析。尽管空间效应可能相当大,但AcOEt–AcOPr i –AcOBu t系列中的显着速率增加主要是由于极性效应。甲基本原理提出了明显不一致:在Rα烷基化的速率的效果比在更大的小号Ñ RBR的1型溶剂分解,这表明大的电荷分离ACO -,R +在协调一致β过渡态-消除,而对于例如AcOCH(Me)C 6 H 4 Z的热解观察到的Hammettρ值只是与苄基碳正离子形成相关的哈密特ρ值的百分之几。
Carboxy and substituted carboxy alkanoyl and cycloalkanoyl peptides
申请人:E. R. Squibb & Sons, Inc.
公开号:US04499079A1
公开(公告)日:1985-02-12
Peptides of the formula ##STR1## wherein X is various amino or imino acids or esters are useful as hypotensive agents.
公式为##STR1##的肽,在其中X是各种氨基或亚氨基酸或酯,可用作降压剂。
Organometallic compounds of Group III. Part 43. Alkylenation with geminal dialuminoalkane reagents: the synthesis of olefins from ketones
作者:Andrzej M. Piotrowski、Dennis B. Malpass、Marek P. Boleslawski、John J. Eisch
DOI:10.1021/jo00247a032
日期:1988.6
THE DEHYDRATION OF 2,3,4-TRIMETHYLPENTANOL-3<sup>1</sup>