Synthesis of Triarylmethanes by Palladium-Catalyzed C–H/C–O Coupling of Oxazoles and Diarylmethanol Derivatives
摘要:
A PdCl2(MeCN)2/PPhCy2 catalyst couples oxazoles with diarylmethyl carbonates or pivalates to form the corresponding triarylmethanes in good yields. The catalysis involves successive secondary benzylic sp(3) C-O and heteroaromatic sp(2) C-H cleavages and provides an effective access to heteroarene-containing triarylmethanes from nonhalogenated and nonmetalated starting materials, which is complementary to precedented cross-coupling technologies with organic halides and organometallic reagents.
commercially available aldehydes (ketones) and benzylic alcohols can be readily arylated to provide a general and scalable access to structurally diverse alcohols (97 examples, >10 gram‐scale). More importantly, convergentpairedelectrolysis, the ideal but challenging electrochemical technology, was employed to transform low‐value alcohols into more useful alcohols. Detailed mechanism study suggests that two
Photo-induced reductive cross-coupling of aldehydes, ketones and imines with electron-deficient arenes to construct aryl substituted alcohols and amines
Abstract Umpolung reactions of C=X bonds (X = O, N) are valuable ways of constructing new C–C bonds, which are sometimes difficult to be constructed using traditional synthetic pathways. Classical polarity inversion of C=X bonds (X = O, N) usually requires air or moisture-sensitive and strong reducing agents, which limit the feasibility of substrate scope. Herein we describe a photo-induced reductive