Pd(II)-Catalyzed Intramolecular Amidoarylation of Alkenes with Molecular Oxygen as Sole Oxidant
摘要:
Stereoselective palladium-catalyzed synthesis of structurally versatile indoline derivatives, using molecular oxygen as the sole oxidant, is described. New C-N and C-C bonds form across an alkene in an intramolecular manner. The C-N bond-forming step proceeds via a syn-amidopalladation pathway. The moderate kinetic isotope effects (intramolecular KIE = 3.56) suggest that electrophilic aromatic substitution occurs in the arylation step.
Acyclic Stereoselection in the Ortho Ester Claisen Rearrangement
作者:G. William Daub、James P. Edwards、Carol R. Okada、Jana Westran Allen、Claudia Tata Maxey、Matthew S. Wells、Alexandra S. Goldstein、Michael J. Dibley、Clarence J. Wang、Daniel P. Ostercamp、Steven Chung、Paula Shanklin Cunningham、Martin A. Berliner
DOI:10.1021/jo9614250
日期:1997.4.1
The ortho ester Claisen rearrangement of trisubstituted allylicalcohols exhibits significant levels of diastereoselection. In E allylicalcohols, a 1,3-diaxial interaction develops in the chairlike transition state leading to the anti isomer, rendering the reaction syn selective by a factor of 3-5 to 1. In Zallylicalcohols, the 1,3-diaxial interaction develops in the transition state leading to
Solid-phase synthesis of N,N′ substituted guanidines
作者:Dharmpal S. Dodd、Owen B. Wallace
DOI:10.1016/s0040-4039(98)01197-6
日期:1998.8
An efficient method for the solid-phasesynthesis of substituted guanidines is presented. A variety of alcohols react with resin-bound N,N′-bis(t-butoxycarbonyl)thiopseudourea under Mitsunobu conditions to give the corresponding alkylated thiopseudoureas. The guanidines are liberated from the resin upon exposure to ammonia or primary amines.
Phospinite-imidazolines and metal complexes thereof
申请人:Menges Federik
公开号:US20070010493A1
公开(公告)日:2007-01-11
Compounds of the formulae (I) and (Ia) where X
1
is secondary phosphino; R
3
is a hydrocarbon radical having from 1 to 20 C atoms, a heterohydrocarbon radical which has from 2 to 20 atoms and at least one heteroatorn selected from the group consisting of O, S, NH and NR, or an —SO
2
—R radical; R is C
1
-C
18
-alkyl, phenyl or benzyl; the radicals R
4
are each, or the two radicals R4 together a hydrocarbon radical having from 1 to 20 C atoms; R
01
is a hydrocarbon radical having from 1 to 20 C atoms; and R
02
and R′
o2
are each, independently of one another, a hydrogen atom or independently have the meaning of R
01
, or R
01
and R
02
together with the C atom to which they are bound form a three- to eight-membered hydrocarbon or hetero hydrocarbon ring. The compounds are chiral ligands for complexes of metals of transition groups I and VIII which act as catalysts for asymmetric additions, for example of hydrogen, onto prochiral unsaturated organic compounds.
Z-Retentive Asymmetric Allylic Substitution Reactions of Aldimine Esters under Ru/Cu Dual Catalysis
作者:Hao Song、Muzi Li、Shu-Li You
DOI:10.1021/jacs.3c13548
日期:2024.2.21
Ru/Cu dual catalysis has been applied for Z-retentive asymmetricallylicsubstitution reactions of aldimine esters. This reaction provides an enantioselective synthesis of chiral Z-olefins in high yields (up to 91% yield) with excellent enantioselectivity (up to 98% ee) under mild conditions. The previously unreacted trisubstituted allylic electrophiles under Ir catalytic system are found to be compatible
Ru/Cu双重催化已应用于醛亚胺酯的Z保留不对称烯丙基取代反应。该反应可在温和条件下以高产率(高达 91% 产率)对映选择性合成手性Z-烯烃,并具有优异的对映选择性(高达 98% ee)。发现先前未反应的三取代烯丙基亲电子试剂在 Ir 催化体系下是相容的,提供Z-或E-形式的立体保留产物。直链和支链烯丙基亲电子试剂都是合适的底物,具有优异的反应结果。值得注意的是,Ru 和 Cu 络合物在一锅中添加,简化了该方案的操作,并且在此 Ru/Cu 双催化系统中可以观察到自排序现象。
Benzotriazole-Mediated Synthesis of 2,3-Disubstituted Allylic Alcohols