A novel [4+1] spiroannulation of o‐ & p‐bromophenols with α,β‐unsaturated imines has been developed for the direct synthesis of a new family of azaspirocyclic molecules. Notably, several other halophenols (X=Cl, I) were also applicable for this transformation. Moreover, a catalytic asymmetric version of the reaction was realized with 1‐bromo‐2‐naphthols by using a chiral ScIII/Py‐Box catalyst. Mechanistic
已经开发了一种新颖的[4 + 1]邻和对溴苯酚与α,β-不饱和亚胺螺环合成的方法,用于直接合成新的氮杂螺环分子家族。值得注意的是,其他几种卤代酚(X = Cl,I)也适用于该转化。此外,通过使用手性Sc III / Py-Box催化剂,使用1-溴-2-萘酚实现了反应的催化不对称形式。机理研究表明,该多米诺反应是通过苯酚衍生物在其卤代位置的亲电触发的脱芳香化作用进行的,然后通过基于自由基的S RN 1机理用N-亲核试剂进行卤素置换。
Palladium‐Catalyzed [2+2+1] Spiroannulation via Alkyne‐Directed Remote C−H Arylation and Subsequent Arene Dearomatization
Palladium-catalyzed alkene-directed cross-coupling of aryliodide with another aryl halide through C-H arylation opens a unique avenue for unsymmetrical biaryl-derived molecules. However, homo-coupling of aryliodides often erodes the overall synthetic efficiency. Reported herein is a highly chemoselective Pd0 -catalyzed alkyne-directed cross-coupling of aryliodides with bromophenols, which was subsequently
A highly regioselective Ru(II)-catalyzed [3+2] spiroannulation of 1-aryl-2-naphthols with internal alkynes was developed by using a novel double directing group strategy. This method was compatible with many functional groups, thus affording a variety of sterically congested spirocyclic molecules in high yields.
Asymmetric Suzuki-Miyaura Cross-Coupling for the Synthesis of Chiral Biaryl Compounds as Potential Monophosphine Ligands
作者:Yan-Na Ma、Shang-Dong Yang
DOI:10.1002/chem.201406554
日期:2015.4.27
Efficient asymmetric Suzuki–Miyauracoupling reactions have been employed for the first time to synthesize chiral biaryl compounds with phosphinate groups as chiral auxiliaries. A series of functionalized chiral biaryls are thereby synthesized in excellent yields and good diastereoselectivities (up to >95:5 d.r.) and axially chiral monophosphorus ligands are obtained through further functionalizations