Comparative reactivity of isoelectronic nitrido, methylimido, and oxo complexes of osmium(VI)
作者:Robert W. Marshman、Patricia A. Shapley
DOI:10.1021/ja00179a022
日期:1990.11
The structures, physical properties, and reaction chemistry of isoelectronic alkyl complexes of osmium (VI) are compared. The three, five-coordinate alkyl complexes [NBu 4 n ] [Os(N)(CH 2 SiMe 3 ) 4 ], Os(NMe)(CH 2 SiMe 3 ) 4 , and Os(O)(CH 2 SiMe 3 ) 4 have been characterized by single-crystal X-ray diffraction, NMR, IR, UV-visible spectroscopy, and by electrochemical techniques. All have a square-pyramidal
Hydrosilylation of Carbonyl-Containing Substrates Catalyzed by an Electrophilic η<sup>1</sup>-Silane Iridium(III) Complex
作者:Sehoon Park、Maurice Brookhart
DOI:10.1021/om100818y
日期:2010.11.22
Hydrosilation of a variety of ketones and aldehydes using the cationic iridium catalyst, (POCOP)Ir(H)(acetone)(+), 1, (POCOP = 2,6-bis(di-tert-butyl phosphinito)phenyl) is reported. With triethyl silane, all but exceptionally bulky ketones undergo quantitative reactions employing 0.5 mol% catalyst in 20-30 min at 25 degrees C. Hydrosilation of esters and amides results in over-reduction and cleavage
Mechanistic studies on reaction of [ReH4(η2-H2)(Cyttp)]+ with ketones to give the hydrido-oxo complex [ReH2(O)(Cyttp)]+ (Cyttp=PhP(CH2CH2CH2PCy2)2)
作者:Dean E. Rende、Andrew Wojcicki
DOI:10.1016/j.jorganchem.2004.10.027
日期:2005.2
smaller amounts of other organic products derived by condensation or related reactions of acetone. The presence of C, apparently arising by dehydration of B, points to the formation of 1 equiv. of H2O in the reaction system. Use of acetone-d6 in conjunction with 1(OTf) gives 2(OTf) containing no deuterium, as well as 1 equiv. of each of (CD3)2CHOH/OD and (CD3)2CDOD/OH. Reactions of 1(OTf) with cyclohexanone
机理研究在反应进行[则热4(η 2 -H 2)(Cyttp)]光学传递函数(1(OTF); Cyttp = PHP(CH 2 CH 2 CH 2 PCY 2)2,光学传递函数= O 3 SCF 3)与酮,既整洁的解决方案。的治疗1(OTF)与过量的丙酮在60-65℃,得到[则热2(O)(Cyttp)]光学传递函数(2(OTF))以高收率,几乎1当量。为h 2,2当量。的2-丙醇,1个当量。每4-羟基-4-甲基-2-戊酮(中的乙)和4-甲基戊-3-烯-2-酮(Ç),和较少量的其它有机产物衍生通过缩合或丙酮的相关反应。的存在Ç,由脱水引起的明显乙,点1个当量的形成。为h 2在反应系O。使用丙酮-d的6会同1(OTF)给出2(OTF)不含有氘,以及1个当量。的每个(CD的3)2 CHOH / OD和(CD 3)2 CD 3 OD / OH。的反应1用环己酮(OTF),环己酮,包括-2,2,6,6-
Cascade Reactions for the Continuous and Selective Production of Isobutene from Bioderived Acetic Acid Over Zinc-Zirconia Catalysts
作者:Anthony J. Crisci、Herui Dou、Teerawit Prasomsri、Yuriy Román-Leshkov
DOI:10.1021/cs501018k
日期:2014.11.7
isobutene over a ZnxZryOz binary metal oxide. The reaction proceeds via a three-step cascade involving ketonization, aldol condensation, and C–C hydrolytic bond cleavage reactions, which was corroborated by isotopic labeling studies. Separately, ZnO and ZrO2 are incapable of producing isobutene from either acetic acid or acetone. In contrast, under optimal conditions, a Zn2Zr8Oz catalyst generates
生物油(通过生物质快速热解获得)含有高浓度的乙酸,这会导致与其存储和处理有关的问题。在Zn x Zr y O z二元金属氧化物上,将乙酸直接升级为异丁烯。反应通过三步级联进行,涉及酮化,羟醛缩合和C–C水解键裂解反应,这已通过同位素标记研究得到证实。单独地,ZnO和ZrO 2不能从乙酸或丙酮生产异丁烯。相反,在最佳条件下,Zn 2 Zr 8 O z催化剂产生一个ca。50%的异丁烯产率,相当于理论最大值的75%。光谱研究表明,要使异丁烯的产量最大化,就需要平衡浓度的酸和碱。
Conformational Analysis, Thermal Rearrangement, and EI‐MS Fragmentation Mechanism of (1(10)
<i>E</i>
,4
<i>E</i>
,6
<i>S</i>
,7
<i>R</i>
)‐Germacradien‐6‐ol by
<sup>13</sup>
C‐Labeling Experiments
作者:Patrick Rabe、Lena Barra、Jan Rinkel、Ramona Riclea、Christian A. Citron、Tim A. Klapschinski、Aron Janusko、Jeroen S. Dickschat
DOI:10.1002/anie.201507615
日期:2015.11.2
diphosphate) and (13C15)FPP were synthesized and enzymatically converted. The products were analyzed using various NMR techniques, including 13C, 13C COSY experiments. The (13C)FPP isotopomers were also used to investigate the thermal rearrangement and EI fragmentation of the enzyme product.
来自鼠链霉菌的未鉴定的萜烯环化酶被鉴定为(+)-(1(10)E,4 E,6 S,7 R)-germacradien-6-ol合酶。酶产物以两个可相互转化的构象体形式存在,从而产生复杂的NMR光谱。为了完全分配NMR数据,合成了所有15种(13 C 1)FPP同位素异构体(FPP =法呢基二磷酸酯)和(13 C 15)FPP并进行了酶促转化。使用各种NMR技术(包括13 C, 13 C COZY实验)对产物进行分析。(13C)FPP同位素异构体也用于研究酶产物的热重排和EI断裂。