Reductions with NADH models. 3. The high reactivity of Hantzsch amides
摘要:
Aromatic ketones and aldehydes are rapidly reduced to alcohols by various 1,4-dihydropyridines, several of which can be considered to be a model of the coenzyme NADH. The reducing agents bear amide groups and are closely related to Hantzsch esters. They exhibit the highest reactivity among NADH models so far described. In some cases, the rate and completeness of reduction by Hantzsch amides compare favorably with those of reduction by the usually employed metal hydrides.
A highly efficient transfer hydrogenation of quinolines with Hantzsch ester as hydrogen source in the presence of 1 mol% Fe(OTf)2 under mild conditions has been developed. A series of substituted 1,2,3,4-tetrahydroquinoline derivatives were afforded in excellent yields with good functional group tolerance.
Provided herein are processes for synthesizing intermediates useful in preparing Mcl-1 inhibitors. In particular, provided herein are processes for synthesizing compound D, wherein OPG and R1 are described herein. Compound D can be useful in synthesizing compound A1, or a salt of solvate thereof, and compound A2, or a salt of solvate thereof.