Remarkably, despite this lack of solubility, 27 underwent a Kumada Corriu coupling with a simple solubilising group using Organ's PEPPSI-IPr catalyst, affording 28 in excellent isolated yield.
The known instability of carbonates pushed Agrofoglio's team to find milder reaction conditions; thus, the preparation of bis(POC -prodrugs was achieved by using IPOC -prodrugsne catalyst B at room temperature (Scheme 19).
Arylboron compounds 17– 19 were coupled with iodoarenes 20 to give biaryl compounds 21 using the air- and moisture-stable palladium N-heterocyclic carbene catalyst PEPPSI- iPr,[ 37] either under thermal or microwave conditions (Scheme 4 and Figure 2).
The IPR-as-a-catalyst approach prefers the IPR regime to remain as the status quo and that the climate change regime construct an enabling environment by lowering the transaction costs of technology transfer and enhancing the regulatory capacity of developing countries.
The zinc alkoxide complex prepared in situ from the reaction of (BDI Zn(N(SiMe3)2) (BDI = 2-((2,6-diisopropylphenyl)amido -4-((2,6-diisopropylphenyl)imino)-2-pentene) with ROH (R = iPr or Bn = CH2Ph) is amido -4-ent catalyst for both the solution and bulk ring-opening polymerization (ROP) of racemic-β-butyrolactone (BBL).
Compound 2 was subjected to a Suzuki coupling with 5-acetyl-2-thienylboronic acid (3) using K2CO3 and the palladium-catalyst PEPPSI™-IPr.
The isospecific rac- EBI Zr NMe2)2/Al(i-Bu)3/[Ph3C][B(C6F6)4] catalyst showed much higherac- EBI Zr NMe2 activity than syndiospecific iPr(Cp)(Flu)ZrMe2/Al(i-Bu)3/[Ph3C6F6 46F6)4] catalyst; however, the latter catalyshowedwed much higher comonomer reactivity, resulting in rE=17.44 and r1,5-HD=0.02(rE×r1,5-HD=0.35), than the latter catalyst showing rE=4.48 and r1,5-HD=0.12(rE×r1,5-HD=0.54).
For example, it was shown that a gold complex with IPr (1,3-bis(2,6-diisopropylphenyl)imidazolidene) as the ligand was the best catalyst for the cyclopropanation of cis-stilbene,[ 18] which is a typical carbene-type transformation (Scheme 6).
Using the second generation Grubbs' catalyst RuCl2(C21H26N2)(CHPh PCy3 (Cy = cyclohexyl) and Hoveyda Grubbs' catalyst RuCl2(C21H26N2){CH-C6H4 O-iPr -2}, the reactions were performed with various C-allylated and O-allylated derivatives of trimethylhydroquinone-1-acetate as substrates.
