Regiocontrolled Coupling of Aromatic and Vinylic Amides with α-Allenols To Form γ-Lactams via Rhodium(III)-Catalyzed C–H Activation
作者:Zhi Zhou、Guixia Liu、Xiyan Lu
DOI:10.1021/acs.orglett.6b02903
日期:2016.11.4
rhodium(III)-catalyzed C–H activation has been demonstrated. This [4 + 1] annulationreaction provides an efficient method for the synthesis of isoindolinones and 1,5-dihydro-pyrrol-2-ones bearing a tetrasubstituted carbon atom α to the nitrogen atom with good functional group tolerance. The hydroxyl group in the allene substrate is essential in controlling the chemo- and regioselectivity of the reaction probably by
Catalytic Asymmetric Allenylation of Malonates with the Generation of Central Chirality
作者:Qiankun Li、Chunling Fu、Shengming Ma
DOI:10.1002/anie.201204346
日期:2012.11.19
Water plays an important role in a palladium‐catalyzed allenylation of diethyl malonate with 2,3‐allenyl acetates to yield centrallychiral allenyl malonates bearing synthetically useful functional groups (see scheme). The products were formed with 92–96 % ee in the presence of a bulky, electron‐rich biphenyl ligand at room temperature.
A stereospecific synthesis of 1,2-disubstituted homopropargylic protected alcohols from bromoallenols
作者:Nicolas Bernard、Fabrice Chemla、Jean F. Normant
DOI:10.1016/s0040-4039(99)00078-7
日期:1999.2
Bromoallenols derived from propargylic epoxides are transformed in two steps and in a stereospecific fashion into 1,2-disubstitutedhomopropargylic protected alcohols with Grignard reagents with or without copper salts.
A practical procedure of propargylation of aldehydes
作者:Papiya Ghosh、Angshuman Chattopadhyay
DOI:10.1016/j.tetlet.2012.07.021
日期:2012.9
An operationally simple procedure of propargylation of aldehydes in moist solvent (distilled THF) has been developed through direct addition of propargyl bromide to aldehyde substrates mediated with low valent iron or tin. The metals were spontaneously prepared in situ employing bimetal redox strategy. Using different aldehydes as substrates (3a–k) both these metal mediated reactions took place producing
HIGHLY REGIOSELECTIVE AND STEREOSELECTIVE RADICAL ADDITION OF<i>p</i>-TsBr TO α-ALLENIC ALCOHOLS AND THEIR ELIMINATION REACTION: SYNTHESIS OF β-<i>p</i>-TOSYL-SUBSTITUTED α,β-UNSATURATED KETONES
作者:Suk-Ku Kang、Byung-Su Ko、Dong-Min Lee
DOI:10.1081/scc-120014030
日期:2002.1
ABSTRACT Regio- and stereoselective radical addition of α-allenicalcohols with p-TsBr in the presence of a catalytic amount of AIBN afforded (E)-γ-bromo-β-sulfonyl allylic alcohols in moderate yields. The base-promoted 1,4-elimination followed by isomerization to give β-sulfonyl-α,β-unsaturated ketones is described.