Cross-Coupling Reactions of Two Different Activated Alkenes through Tetrabutylammonium Fluoride (TBAF) Promoted Deprotonation/Activation Strategy: A Regioselective Construction of Quaternary Carbon Centers
摘要:
A novel TBAF-promoted intermolecular crossed-conjugate addition has been developed. For a range of cyclic beta-halo-alpha,beta-unsaturated carbonyl compounds, the vinylogous enolates generated by deprotonation at the gamma-position preferentially reacted with Michael acceptors at the alpha-position to deliver cross-coupling products in good yields.
Synthesis of 2-Mercaptobenzaldehyde, 2-Mercaptocyclohex-1-enecarboxaldehydes and 3-Mercaptoacrylaldehydes
作者:Qingfen Niu、Xiaofeng Xu、Hongjian Sun、Xiaoyan Li
DOI:10.1002/cjoc.201200433
日期:2012.10
for the preparation of 2‐mercaptobenzaldehyde, 2‐mercaptocyclohex‐1‐enecarboxaldehydes and 3‐mercaptoacrylaldehydes [(Z)‐3‐mercapto‐2‐methyl‐3‐phenylacrylaldehyde, 3‐mercapto‐3‐(o‐tolyl)acrylaldehyde)] starting from ortho‐bromobenzaldehyde, 2‐chlorocyclohex‐1‐enecarbaldehydes, (Z)‐3‐chloro‐2‐methyl‐3‐phenylacrylaldehyde and 3‐chloro‐3‐(o‐tolyl)acrylaldehyde is reported. The reaction of sulfur with the
(4), [CoClMe(PMe3)2–(C6H8)–CH=O}] (5), and [CoClMe(PMe3)2–(C6H7Memeta)–CH=O}] (6) were synthesized through cyclometalation reactions with aldehyde as an anchoring group involving aliphatic vinylic C–Cl bond activation. Complexes 4–6 were characterized by IR and NMR spectroscopy. The crystal and molecular structures of complexes 4 and 5 were determined by single-crystal X-ray diffraction. Complexes
The patent discloses a novel metal free process for the preparation of corresponding phenol and ketone via allylic oxidation of substituted cyclohexenes. Air is used as oxidant in the present process and can be used as such or optionally selected from pure oxygen or atmospheric oxygen. Moreover, the process of the present invention utilizes easily available starting materials and is a green eco-friendly, convenient and economical process with high yield of >60% and high selectivity