Question

Advanced Synthesis Laboratory Experiment 13. Alkene Isomerization by a Homogeneous Nickel Catalyst This experiment was taken from Birdwbisell, K. R.; Lanva, J. J. Chem. Educ. 1997, 74, 579.81 and modified to fit our course hoars and available instrumentation Introduction Alkenes are among the most versatile and useful building blocks of organic molecules, which are used in industry and small scale organic synthesis. Transition metal catalysts can be used to initiate reactions such as hydroformylation, hydrogenation, and the polymerization of alkenes. In many cases the position of the double bond in a longer carbon chain is of critical importance to form the desired products. Therefore, many processes make use of an alkene isomerization reaction, in which a terminal alkene is transformed into an internal alkene, or vice versa. Such a reaction is also best carried out in the presence of a transition metal catalyst. N?Cl2 . 6 H2O + 5 P(OEt)3 + 2 HNEt2 Ni[P(OEt)342 (H2NEt )CI+(EtO) PO) +5 H2O (13-1) In this experiment,a nickel phosphite complex, Ni[POEt)J is prepared as a precatalyst and used to generate a homogeneous catalyst active for the isomerization of alkenes, proposed to be The isomerization of 1-heptene is initiated by adding H2SO, to an ether solution of 1-heptene and Ni[P(OE)], producing [ {(EtO)3P) 3NiH]+ in sin: (13-2) State University of New York at Albany

1. What is meant by the term precatalyst? Draw the structure of the catalyst that actively performs the isomerization of 1-heptene.

2. What is the oxidation state of nickel in NiCl2, the precatalyst, and the active catalyst?

3. Is the reaction for the formation of the catalyst (13-2) an oxidation/reduction reaction? If so, what is being oxidized and what is being reduced?

I frankly don't even know where to begin. Thank you in advance; all the information I have is included.

Answer 1

リdt can be defined 03, ang chanical Co. Can be convertes t a Caka Rdtng oChemical chanfeJ.s caled PA Precatrigle, Becaude after ahstrachn a froten dueing ReacGHen cakoldt, HN,[P@et) 3) Se s an ori dobion Reduchion Reactron. Niw getting Reduced