Selective Isomerization of Terminal Alkenes to (<i>Z</i>)-2-Alkenes Catalyzed by an Air-Stable Molybdenum(0) Complex
作者:Joseph Becica、Owen D. Glaze、Derek I. Wozniak、Graham E. Dobereiner
DOI:10.1021/acs.organomet.7b00914
日期:2018.2.12
Positional and stereochemical selectivity in the isomerization of terminal alkenes to internal alkenes is observed using the cis-Mo(CO)4(PPh3)2 precatalyst. A p-toluenesulfonic acid (TsOH) cocatalyst is essential for catalyst activity. Various functionalized terminal alkenes have been converted to the corresponding 2-alkenes, generally favoring the Z isomer with selectivity as high as 8:1 Z:E at high
使用顺式-Mo(CO)4(PPh 3)2预催化剂观察到末端烯烃异构化为内部烯烃的位置和立体化学选择性。甲p -甲苯磺酸(TsOH)助催化剂为催化剂活性是必需的。各种官能化的末端烯烃已被转化为相应的2-烯烃,在高转化率下通常有利于Z异构体,其选择性高达8:1 Z:E。通过31 P NMR对催化剂引发机理的研究表明,顺式-Mo(CO)4(PPh 3)2在高温下与TsOH反应生成磷化氢键合的Mo氢化物(MoH)物种。催化可通过将末端烯烃的2,1-插入MoH基团和立体选择性β-氢化物消除以产生(Z)-2-烯烃来进行。
Diastereoselective Singlet Oxygen Ene Reaction (Schenck Reaction) and Diastereoselective Epoxidations of Heteroatom-Substituted Acyclic Chiral Olefins: A Mechanistic Comparison
作者:Waldemar Adam、Hans-Günter Brünker、A. Sampath Kumar、Eva-Maria Peters、Karl Peters、Uwe Schneider、Hans Georg von Schnering
DOI:10.1021/ja9530230
日期:1996.1.1
The directing propensity of allylic and homoallylic heteroatom substituents on the diastereoselective singlet oxygen enereaction (Schenck reaction) of acyclic, chiral olefins has been investigated. These extensive stereochemical results offer evidence for our proposed mechanism of the diastereoselective singlet oxygen enereaction. Thus, provided a substrate possesses sufficient 1,3-allylic strain
Synthesis of Optically Active α-Methyl β-Hydroperoxy Esters by Diastereoselective Singlet Oxygen Ene Reaction and Horseradish Peroxidase Catalyzed Kinetic Resolution
作者:Waldemar Adam、Chantu R. Saha-Möller、Oliver Weichold
DOI:10.1007/s007060070098
日期:2000.6.15
Optically active diastereomeric β-hydroperoxy esters 4 have been prepared by singletoxygenenereaction of β,γ-unsaturated esters 3 and subsequent horseradish peroxidase (HRP) catalyzed kinetic resolution of the eneproduct. The highest enantiomeric excess (up to 95%) has been obtained for the isopropyl ester threo - 4c , which establishes that the size of the remote ester functionality exercises
Flavoring compositions containing alkyl esters of 2-methyl-4-pentenoic
申请人:International Flavors & Fragrances Inc.
公开号:US03976801A1
公开(公告)日:1976-08-24
Methods are described for adding 2-methyl-4-pentenoic acid and/or C.sub.2 -C.sub.6 alkyl esters thereof to foodstuffs, chewing gums or medicinal products in order to impart sweet, fruity, strawberry, winey-cognac, pineapple-like, pear, green and/or apple-like aromas and tastes; with cooked strawberry jam undertones to said foodstuffs, chewing gums or medicinal products.
Novel process for altering the organoleptic properties of tobacco using
申请人:International Flavors & Fragrances Inc.
公开号:US03987803A1
公开(公告)日:1976-10-26
Described is a process comprising adding to tobacco (for subsequent incorporation into smoking articles along with tobacco blend) an amount sufficient to alter the flavor or aroma of the tobacco of 2-methyl-4-pentenoic acid and/or ethyl-2-methyl-4-pentenoate.