Synthesis of Novel Ferrocenyl‐Based P,S Ligands (ThioClickFerrophos) and Their Use in Pd‐Catalyzed Asymmetric Allylic Substitutions

Abstract

A series of P,S ligands (ThioClickFerrophos) based on a triazoleferrocenylethyl backbone were synthesized in a fourstep sequence by click chemistry methodology. The new P,S ligands were applied in allylic alkylations, etherifications, and aminations of 1,3-diphenylprop-2-enyl acetate catalyzed

10 Years of Click Chemistry: Synthesis and Applications of Ferrocene‐Derived Triazoles

“…The synthesis of thioclickferrophos (TCFP) ligand involved the same strategy as clickferrophos, by which the lithiated ferro- cenyl triazole moiety was quenched with various disulfides to achieve a family of thioclickferrophos ligands (Scheme 29). [38] The TCFP ligands were studied for their catalytic activity and asymmetric induction on the same set of reactions as CFP ligands to compare the efficiency of the catalysts. Ligands 76 a-f were screened for the alkylation of allyl acetate with [{PdA C H T U N G T R E N N U N G (h 3 -C 3 H 5 )Cl} 2 ].…”

“…Similarly, an asymmetric amination reaction under the same conditions resulted in 66 % ee (Scheme 31). [38] Then thioclickferrophos was employed in the 1,3-dipolar cycloaddition of N-benzylidineglycinate and a-enones and other dipolarophiles. An earlier report by Fukuzawa et al demonstrated an exo selectivity when a combination of Cu I and clickferrophos were used.…”

“… As sulfur is considered to be a soft atom, it can bind soft metals such as palladium and copper strongly, which can help enhance the enantioselectivity. The synthesis of thioclickferrophos (TCFP) ligand involved the same strategy as clickferrophos, by which the lithiated ferrocenyl triazole moiety was quenched with various disulfides to achieve a family of thioclickferrophos ligands (Scheme ) 38…”

Palladium-Catalyzed Enantioselective Allylic Substitution

“…A maximal ee of 90% was recorded in standard AAA reactions [120]. Chan and co-workers also altered their design of L81-L83 and came up with ligand L85, where the phosphorus and sulfur atoms were separated by four A sugar-based P-S ligand L86 has been developed by Khiar and co-workers (Fig.…”

One-Pot Reaction for Synthesis of 1,2,3-Triazole Thioethers from Iodotriazole, Sulfur and Alkylhalides/Tosylates

“…[7] However, the corresponding protocols for the synthesis of fully substituted 1,2,3-triazoles via Huisgen reaction remain a challenge [8] due to the increased energy barrier (270 kJ mol -1 ), [9] particularly for the synthesis of 5-thio-1,2,3-triazoles. 1,2,3-Triazoles bearing a 5-sulfur substituent represent to be a series of useful molecules, [10] for example, using as an excellent chiral ligand in organic synthesis [11] and potential antifungal agents. [12] Recently, Ding reported a method of Iridium-catalyzed cycloaddition of thioalkynes with azide [13] .…”