Naphthalene-catalysed lithiation of functionalized chloroarenes: regioselective preparation and reactivity of functionalized lithioarenes
摘要:
The lithiation of different functionalized chloroarenes (dichlorobenzenes 1 and 3. mono and dichlorophenols 9 and 14, and chloropivalanilides 18) in the presence of a catalytic amount of naphthalene leads to the corresponding functionalized lithioarenes, which react with electrophiles to give the expected polyfunctionalized aromatic molecules 2, 4, 10. 19, 21, 22 and 24 in a regioselective manner. In the case of starting from chlorinated phenols or anilides a deprotonation of the functional group is carried out prior to the lithiation process; only for 2-chloropivalanilide 18o a coupling reaction leading to 2-n-butylpivalanilide is observed when an excess of n-butyllithium is used in the deprotonation step.
17BETA-HYDROXYSTEROID DEHYDROGENASE TYPE 3 INHIBITORS FOR THE TREATMENT OF ANDROGEN DEPENDENT DISEASES
申请人:SCHERING CORPORATION
公开号:EP1423381B1
公开(公告)日:2007-01-03
US7432268B2
申请人:——
公开号:US7432268B2
公开(公告)日:2008-10-07
Organocatalytic Enantioconvergent Synthesis of Tetrasubstituted Allenes via Asymmetric 1,8-Addition to aza-<i>para</i>-Quinone Methides
作者:Min Chen、Deyun Qian、Jianwei Sun
DOI:10.1021/acs.orglett.9b03224
日期:2019.10.4
In contrast to the well-explored quinone methides (QMs) and aza-ortho-QMs, aza-para-QMs have been rarely studied in terms of their asymmetric transformations. Herein, a highly efficient enantioconvergent asymmetric 1,8-addition of aza-para-QMs is described. Featuring remarkable remote stereocontrol, this reaction provides expedient access to chiral tetrasubstituted allenes bearing an adjacent all-carbon
Naphthalene-catalysed lithiation of functionalized chloroarenes: regioselective preparation and reactivity of functionalized lithioarenes
作者:Albert Guijarro、Diego J Ramón、Miguel Yus
DOI:10.1016/s0040-4020(01)80314-8
日期:1993.1
The lithiation of different functionalized chloroarenes (dichlorobenzenes 1 and 3. mono and dichlorophenols 9 and 14, and chloropivalanilides 18) in the presence of a catalytic amount of naphthalene leads to the corresponding functionalized lithioarenes, which react with electrophiles to give the expected polyfunctionalized aromatic molecules 2, 4, 10. 19, 21, 22 and 24 in a regioselective manner. In the case of starting from chlorinated phenols or anilides a deprotonation of the functional group is carried out prior to the lithiation process; only for 2-chloropivalanilide 18o a coupling reaction leading to 2-n-butylpivalanilide is observed when an excess of n-butyllithium is used in the deprotonation step.