70039-16-6

Upstream product

• 128-39-2 2,6-di-tert-butylphenol 
• 587-04-2 m-Chlorobenzaldehyde 

Relevant academic research and scientific papers

1,6-Addition Arylation of para-Quinone Methides: An Approach to Unsymmetrical Triarylmethanes

A 1,6-addition arylation reaction of para-quinone methides with α-isocyanoacetamides and electron-rich aromatic compounds under metal-free conditions has been developed. BF3·Et2O plays two roles in the reaction: catalyzing the cyclization of α-isocyanoacetamides to give oxazoles, and activating the para-quinone methides to achieve the 1,6-addition arylation process. The reaction shows good functional group tolerance, scalability, and regioselectivity. It is a consice protocol for the synthesis of diverse unsymmetrical triarylmethanes. Further transformation of the resulting triarylmethanes provides an efficient route to some functionalized molecules.

Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: Easy access to C3-functionalized triarylmethane imidazopyridine

An inexpensive and commercially available Tf2NH-catalyzed 1,6-conjugate addition of imidazopyridine (IMPY) heterocycles to para-quinone methides (p-QMs) is reported. The present transformation provides a diverse class of C3-functionalized triarylmethanes heterocyclic derivatives of imidazopyridine. These metal-free transformations provided a very broad substrate scope of conjugate addition product with a high yield up to 97% within a short duration.

Iron-Catalyzed Ring Opening of Cyclopropanols and Their 1,6-Conjugate Addition to p-Quinone Methides

A novel iron-catalyzed ring opening of cyclopropanols and their 1,6-conjugate addition to p-quinone methides for accessing substituted phenols is disclosed. In this protocol, various cyclopropanols are converted to alkyl radicals and undergo 1,6-conjugate addition to p-quinone methides toward C–C bond formation. The salient features of this methodology include operationally simple and mild reaction conditions, environmentally benign protocol, high efficiency, inexpensive catalyst, good to excellent yield, and a wide range of substrate scope.

Organocatalytic Enantioselective 1,6-aza-Michael Addition of Isoxazolin-5-ones to p-Quinone Methides

A thiourea-Br?nsted base bifunctional catalyst allowed the enantioselective 1,6-aza-Michael addition of isoxazolin-5-ones to p-quinone methides to give isoxazolin-5-ones having a chiral diarylmethyl moiety attached to the N atom with fair to good yields and enantiomeric excesses. To the best of our knowledge this reaction represents the first example of enantioselective N-alkylation of isoxazolin-5-ones as well as the first example of enantioselective 1,6-aza-Michael reaction involving p-quinone methides.

A new approach to access difluoroalkylated diarylmethanes: Via visible-light photocatalytic cross-coupling reactions

Difluoroalkylated diarylmethanes with biological and pharmacological potentials were synthesized from para-quinone methides (p-QMs) and difluoroalkylating reagents via a visible light photocatalysis strategy. Mechanism studies showed that the excited photocatalyst, ?fac-Ir(ppy)3, was primarily quenched by p-QMs and the generated diarylmethane radical intermediates then underwent a radical-radical cross-coupling reaction with difluoroalkyl radicals. This reaction features mild conditions, high efficiency and wide functional group compatibility.

Direct access to α,α′-diarylated ketones through N-heterocyclic carbene-catalyzed 1,6-addition of aromatic aldehydes to para-quinone methides

N-Heterocyclic carbene-catalyzed 1,6-addition of aromatic aldehydes to para-quinone methides has been developed. This method could efficiently furnish α,α′-diarylated ketones with good to high yields, which contain various functional groups.

Organocatalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins

A chiral thiourea catalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins has been developed. The reaction provided an efficient approach to the synthesis of chiral diarylmethine skeletons in good yields (up to 99% yield) with high diastereo- and enantioselectivity (>20:1 dr and up to 99.5:0.5 er), also on a gram scale. The preliminary mechanistic study showed that the remote stereocontrol was achieved through intermolecular hydrogen-bond interaction between the chiral thiourea catalyst and the para-quinone methides directly for the first time.

Synthesis of spiro[2.5]octa-4,7-dien-6-one with consecutive quaternary centers via 1,6-conjugate addition induced dearomatization of para-quinone methides

An efficient one-pot approach for the synthesis of spiro[2.5]octa-4,7-dien-6-ones by employing para-quinone methides has been developed. The reaction proceeded smoothly in high yields under mild conditions without the use of metals. Moreover, all products obtained herein contained two or three consecutive quaternary centers.

1,6-Conjugated Addition-Mediated [2+1] Annulation: Approach to Spiro[2.5]octa-4,7-dien-6-one

A formal 1,6-conjugated addition-mediated [2+1] annulation to synthesize spiro[2.5]octa-4,7-dien-6-one with p-quinone methides and sulfur ylides has been described. This domino-type process was highly diastereoselective and exhibited good functional group tolerance and scalability without the use of metals and bases.