Methods for meta-arylation of aromatic alcohols
Provided are methods for the meta-selective C—H arylations of arene alcohol-based substrates. The methods combine the transient norbornene strategy with a quinoline-based acetal scaffold to achieve the formation of biaryl compounds. These processes establish a foundation for catalytic polyfunctionalization of alcohol-based compounds. The method comprises attaching a heterocyclic hemiacetal scaffold to an aromatic alcohol or a substituted aromatic alcohol; reacting the aromatic or substituted aromatic alcohol having the heterocyclic hemiacetal scaffold attached with an alkyl or aryl iodide in a reaction mix comprising a palladium catalyst, a silver salt, and carboxymethyl norbornene to generate a meta-arylated arene conjugated to the heterocyclic hemiacetal scaffold; and then cleaving the heterocyclic hemiacetal scaffold from the meta-arylated arene alcohol.
1. A method of meta-arylating an arene alcohol, the method comprising the steps of:
(a) replacing a benzoate group of a quinolinyl hemiacetal benzoate with an aromatic alcohol or a substituted aromatic alcohol wherein the aromatic alcohol or a substituted aromatic alcohol has the formula II:
thereby forming form a compound of formula III:
(b) reacting the compound of formula III with an aryl iodide having the formula I:
in the presence of a palladium trifluoroacetate catalyst, silver acetate, trifluoroacetylglycine, and carboxymethyl norbornene to generate a meta-arylated arene-quinolinyl hemiacetal scaffold conjugate; and
(c) incubating the meta-arylated arene-quinolinyl hemiacetal scaffold conjugate of step (b) with an alkyl alcohol under acid conditions to generate an alkylated quinolinyl hemiacetal scaffold having the formula V:
and a meta-arylated arene alcohol having the formula VI:
wherein:
R 1 , R 2 , or R 3 are independently selected from the group consisting of: H, a halogen, an alkyl, a substituted alkyl, an aryl, a substituted aryl, an amino group, a substituted amino group, an alkoxy group, a heterocyclic group, R 1 and R 2 are linked to form a cyclic group and R 2 and R 3 are linked to form a cyclic group; and
R 4 is selected from the group consisting of: H, a halogen, an alkyl, an alkoxy, a carboxyalkyl, an alkylbenzoate, a substituted amine, an ether group, a ketone group, an ester group, a carbamate group, a nitro group, and a halogenated alkyl group.
2. The method of claim 1 , wherein the aryl iodide is an alkyliodobenzoate.
3. The method of claim 2 , wherein the alkyliodobenzoate is methyliodobenzoate.