Silyl Phosphites. XVIII. Versatile Utility of α-(Trimethylsilyloxy)alkylphosphonates as Key Intermediates for Transformation of Aldehydes into Several Carbonyl Derivatives
作者:Mitsuo Sekine、Masashi Nakajima、Akiko Kume、Akio Hashizume、Tsujiaki Hata
DOI:10.1246/bcsj.55.224
日期:1982.1
trimethylsilyl phosphite (DTMSP) with aldehydes were converted, by treatment with lithium diisopropylamide (LDA) followed by the successive alkylation and alkalinehydrolysis, to carbonyl derivatives involving aldehydes, unsymmetrical ketones, β,γ-unsaturated ketones, and carboxylic acids. β-Substituted carboxylic esters and γ-substituted lactones were prepared by use of the carbonyl addition compounds of DTMSP
A new radical cyclization method for the formation of C(sp3)–C(sp3) and C–O bonds via MnO2-promoted alkene carboesterification with anhydrides is developed.
Kinetic Resolution and Dynamic Kinetic Resolution of γ‐Aryl‐Substituted Butenolides via Copper‐Catalyzed 1,4‐Hydroboration
作者:Soyeon Lee、Do Hyun Ryu、Jaesook Yun
DOI:10.1002/adsc.202001353
日期:2021.4.27
Kinetic resolution (KR) and dynamic kinetic resolution (DKR) of γ‐aryl and heteroaryl‐substitutedbutenolides via CuH‐catalyzed 1,4‐hydroboration using pinacolborane is reported. With a copper‐Ph‐BPE catalyst, selectivity factors were extremely high (s=>400) with regard to the kinetic resolution of β‐methyl‐γ‐phenyl butenolide; DKR was possible in the presence of an amine base (DBU), which facilitated racemization
Ni(acac)(2) catalyzes homoallylation of aldehydes with 1,3-dienes in the presence of triethylborane. Triethylborane serves as a reducing agent delivering a formal hydride to the C2 position of 1,3-dienes, thus generating a formal homoallyl anion species and enabling the novelhomoallylation of aldehydes. The reaction proceeds smoothly at room temperature in the absence of any phosphane or nitrogen
Samariumdi-iodide is an efficient reagent for the reductivecoupling of ketones or aldehydes and electron-deficientalkenes, whereby γ-lactones can be prepared in good yields from ethyl acrylate.