One-pot synthesis of substituted flourenes
AssigneeChevron Phillips Chemical Company LP
InventorsChengbao NI, Qing YANG
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Abstract
This disclosure relates to new synthetic methods for preparing substituted fluorene compounds and fluorenyl-substituted metallocenes, which are useful in applications such as olefin polymerization catalysis. The new methods involve a Pd-catalyzed, one-pot tandem reaction of a 1,2-dihalobenzene with a 2-methylarylboronic acid using non-conventional and unexpected reaction conditions, which may improve existing methods by providing higher yields, higher selectivity, and/or the ability to incorporate a wider range of substituents with various steric and electronic properties and regiochemistries which are difficult to access using existing methods.
Claims31
A method of making a fluorene compound, the method comprising:
- (a) combining a substituted or an unsubstituted 1,2-dihalobenzene;
- a base;
- a palladium catalyst;
- a phosphine compound, a phosphite compound, or a phosphonate compound;
- a carboxylic acid;
- and a solvent in a reaction vessel to form a first solution;
- (b) adding an o-tolylboronic acid solution comprising a substituted or an unsubstituted o-tolylboronic acid in a liquid carrier to the first solution over a first time period (Δt1) to form a second solution, wherein the first solution is heated to a first temperature (T1) prior to the addition of the o-tolylboronic acid solution to the first solution or during the addition of at least a portion of the o-tolylboronic acid solution to the first solution;
- (c) maintaining the second solution at the first temperature (T1) for a second time period (Δt2);
- and
- (d) following the second time period, heating the second solution to a second temperature (T2) greater than the first temperature (T1) and maintaining the second solution at the second temperature (T2) for a third time period (Δt3) to form the fluorene compound.
A method of making a fluorene compound, the method comprising:
- (a) combining a substituted 1,2-dihalobenzene;
- a base;
- a palladium catalyst;
- a phosphine compound, a phosphite compound, or a phosphonate compound;
- a carboxylic acid;
- and a solvent in a reaction vessel to form a first solution;
- (b) adding an o-tolylboronic acid solution comprising a substituted or an unsubstituted o-tolylboronic acid in a liquid carrier to the first solution over a first time period (Δt1) to form a second solution, wherein the first solution is heated to a first temperature (T1) from 70° C. to 130° C. prior to the addition of the o-tolylboronic acid solution to the first solution, and wherein the o-tolylboronic acid solution is added to the first solution at a rate of from 0.002 equivalent/minute (eq/min) to 0.2 eq/min;
- (c) maintaining the second solution at the first temperature (T1) for a second time period (Δt2);
- and
- (d) following the second time period, heating the second solution to a second temperature (T2) from 135° C. to 165° C. and maintaining the second solution at the second temperature (T2) for a third time period (Δt3) to form the fluorene compound.
A fluorene compound having the formula:
Dependencies are inferred from the claim text.