- Air-stable nickel precatalysts for fast and quantitative cross-coupling of aryl sulfamates with aryl neopentylglycolboronates at room temperature.
Air-stable nickel precatalysts for fast and quantitative cross-coupling of aryl sulfamates with aryl neopentylglycolboronates at room temperature.
Organic letters (2014-12-04)
Ryan L Jezorek, Na Zhang, Pawaret Leowanawat, Matthew H Bunner, Nicholas Gutsche, Aleksander K R Pesti, James T Olsen, Virgil Percec
PMID25467653
ABSTRACT
A library containing 10 air-stable Ni(II)X(Aryl)(PCy3)2 σ-complexes as precatalysts (X = Cl, Br, OTs, OMs, aryl = 1-naphthyl, 2-naphthyl; X = Cl, 1-acenaphthenyl, 1-(2-methoxynaphthyl), 9-phenanthrenyl, 9-anthracyl) was synthesized and demonstrated to quantitatively cross-couple 2-methoxyphenyl dimethylsulfamate with methyl 4-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)benzoate at 23 °C in dry THF in the presence of K3PO4(H2O)3.2 in less than 60 min. Lower or higher amounts of H2O in K3PO4 and as received THF mediate the same transformation in a maximum three times longer reaction time.