93548-33-5Relevant articles and documents
Kinetic resolution of racemic allylic alcoholsviairidium-catalyzed asymmetric hydrogenation: scope, synthetic applications and insight into the origin of selectivity
Wu, Haibo,Margarita, Cristiana,Jongcharoenkamol, Jira,Nolan, Mark D.,Singh, Thishana,Andersson, Pher G.
, p. 1937 - 1943 (2021/02/22)
Asymmetric hydrogenation is one of the most commonly used tools in organic synthesis, whereas, kinetic resolutionviaasymmetric hydrogenation is less developed. Herein, we describe the first iridium catalyzed kinetic resolution of a wide range of trisubstituted secondary and tertiary allylic alcohols. Large selectivity factors were observed in most cases (sup to 211), providing the unreacted starting materials in good yield with high levels of enantiopurity (ee up to >99%). The utility of this method is highlighted in the enantioselective formal synthesis of some bioactive natural products including pumiliotoxin A, inthomycin A and B. DFT studies and a selectivity model concerning the origin of selectivity are presented.
Catalytic asymmetric addition of aldehydes using organolithium reagents in the presence of commercial available chiral diol ligands
Zong, Hua,Huang, Huayin,Song, Ling
supporting information, p. 1069 - 1074 (2016/10/11)
An efficient method for the catalytic asymmetric additions to aldehydes using organolithium reagents and titanium(IV) isopropoxide in the presence of commercially available and relatively inexpensive diol ligands, such as (S)-BINOL or D-TADDOL has been developed. Good to excellent yields (up to 92%) and enantioselectivities (up to 94%) of the corresponding secondary alcohol products can be obtained following a simple procedure at relatively mild reaction temperatures.
Catalytic enantioselective addition of alkyl grignard reagents to aliphatic aldehydes
Fernandez-Mateos, Emilio,Macia, Beatriz,Yus, Miguel
supporting information, p. 1249 - 1254 (2013/06/27)
Herein, we report an efficient catalytic system for the enantioselective addition of alkyl Grignard reagents to a broad range of aliphatic aldehydes with good yields and enantioselectivities. Remarkably, the challenging methylmagnesium bromide (MeMgBr) can also be added to a variety of aliphatic aldehydes, providing versatile chiral methyl carbinol units with unprecedented yields and enantioselectivities in a simple one-pot procedure under mild conditions. Copyright
Synthesis of alcohols from m-fluorophenylsulfones and dialkylboranes: Application to the C14-C35 building block of E7389
Liu, Lei,Henderson, James A.,Yamamoto, Akihiko,Bremond, Paul,Kishi, Yoshito
, p. 2262 - 2265 (2012/06/30)
The reaction of m-fluorophenylsulfone anions with dialkylboranes, followed by alkaline hydroperoxide oxidation, yields alcohols in high yields. Optimization of the process, scope and limitation, and application to the synthesis of one of the C14-C35 building blocks of E7389, a right half analogue of halichondrin B, are reported.
Catalytic enantioselective addition of MeMgBr and other Grignard reagents to aldehydes
Fernandez-Mateos, Emilio,MacIa, Beatriz,Ramon, Diego J.,Yus, Miguel
supporting information; experimental part, p. 6851 - 6855 (2012/01/03)
Herein, we report an efficient catalyst for the challenging enantioselective addition of MeMgBr to aldehydes. Unprecedented yields and enantioselectivities are achieved in the reaction with a broad range of aldehydes. Moreover, a variety of Grignard reagents can be also added to aromatic and aliphatic aldehydes in good yields and enantioselectivities in a simple one-pot procedure under mild conditions.
A novel one-pot synthesis of secondary alcohols from esters
Chae, Min Jung,Jeon, Ah Ram,Park, Jae Kyo,An, Duk Keun
experimental part, p. 1718 - 1720 (2011/04/25)
Alkylation or vinylation by using organometallic reagents after partial reduction of carboxylic esters with LDBBA gave secondary alcohols, also involving allyl alcohols, without any isolation of intermediates in good yield (54-78%).
Construction of cyclopentyl carbinols from ω-tosyloxy-1-alkenyl boronate esters and grignard reagents
Kobayashi, Yuichi,Asano, Moriteru,Kiyotsuka, Yohei
scheme or table, p. 787 - 791 (2010/09/18)
Addition of RMgCl (R = n-Bu, Ph) to pinacol esters of 6-tosyloxy-l-alkenyl boronic acids at -78 °C gave the borates, which upon warming to room temperature underwent migration of R on boron to C(1) carbon and concomitant ring construction C-C bond formati
Empirical method for predicting enantioselectivity in catalytic reactions: demonstration with lipase and oxazaborolidine
Ema, Tadashi,Ura, Norichika,Yoshii, Masataka,Korenaga, Toshinobu,Sakai, Takashi
experimental part, p. 9583 - 9591 (2010/01/06)
We derived a novel equation capable of predicting the degree of enantioselectivity in a catalytic reaction without any knowledge of the reaction mechanism and/or the transition-state structure, and tested the validity of this equation by changing substrates systematically in the lipase or oxazaborolidine-catalyzed reactions. A good correlation was observed between the predicted and observed E values, and the stereochemistry of the products could be predicted correctly in most cases (28 out of 30).
Pentamethylcyclopentadienide in organic synthesis: Nucleophilic addition of lithium pentamethylcyclopentadienide to carbonyl compounds and carbon-carbon bond cleavage of the adducts yielding the parent carbonyl compounds
Uemura, Minoru,Yagi, Kazunari,Iwasaki, Masayuki,Nomura, Kenichi,Yorimitsu, Hideki,Oshima, Koichiro
, p. 3523 - 3535 (2007/10/03)
Lithium pentamethylcyclopentadienide (C5Me5Li, Cp*Li) reacted with aromatic aldehyde to provide the corresponding carbinol in excellent yield. The carbinol returns to the parent aldehyde and pentamethylcyclopentadiene upon exposure to acid or due to heating. Chlorodimethylaluminum is essential as an additive to attain the nucleophilic addition of Cp*Li to aliphatic aldehyde. The carbinol derived from aliphatic aldehyde returns to the parent aldehyde and pentamethylcyclopentadiene by the action of a catalytic amount of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The reversible addition/elimination of the Cp* group can represent a protection of aldehyde. Mechanistic details of the carbon-carbon bond cleavage are also disclosed.
Highly enantioselective 1,2-additions of various organolithium reagents to aldehydes
Granander, Johan,Eriksson, Jonas,Hilmersson, Goeran
, p. 2021 - 2027 (2007/10/03)
Several asymmetric 1,2-additions of various organolithium reagents (methyllithium, n-butyllithium, phenyllithium, lithioacetonitrile, lithium n-propylacetylide, lithium phenylacetylide) to aldehydes are shown to result in decent to excellent enantiomeric excesses (65-98%) when performed in the presence of a chiral lithium amido sulfide. The chiral lithium amido sulfides invariably exhibited higher levels of enantioselectivity in all the reactions tested, compared to the structurally similar chiral lithium amido ethers and the chiral lithium amide without a chelating group.