52922-10-8Relevant academic research and scientific papers
Chiral bronsted acid-catalyzed allylboration of aldehydes
Jain, Pankaj,Antilla, Jon C.
, p. 11884 - 11886 (2010)
The catalytic enantioselective allylation of aldehydes is a long-standing problem of considerable interest to the chemical community. We disclose a new high-yielding and highly enantioselective chiral Bronsted acid-catalyzed allylboration of aldehydes. Th
ALLYLSTANNATION. I. STEREOCHEMISTRY OF THE ADDITION OF trans/cis-2-BUTENYL-CHLORO-DI-n-BUTYLTIN TO ALDEHYDES
Gambaro, Alessandro,Marton, Daniele,Peruzzo, Valerio,Tagliavini, Giuseppe
, p. 149 - 156 (1982)
2-Butenyl-chloro-di-n-butyltin, in various trans/cis ratios, reacts readily with neat RCHO (R = CH3, C2H5, C2H5(CH3)CH, (CH3)2CH, C6H5) at 25 deg C to give mixtures of threo/erythro-α-methylallylcarbinols in high yields.The same mixtures are obtained from the equilibrated mixtures obtained by redistribution between Bu3SnC4H7 (C4H7 = trans-, cis-crotyl and α-methylallyl group) and Bu2SnCl2.The reactions are characterized by a high degree of stereoselectivity, especially when bulky R groups are present.The complete allylic rearrangement and the stereoselectivity indicate that an exacyclic transition state is involved.Two stereochemically different transition states lead to two diastereoisomers, threo- and erythro-α-methylallylcarbinol in the enantioforms RS, SR and RR, SS, respectively.
Enhancement of threo-Selectivity in the Reaction of But-2-enyl-lithium with Aldehydes via Allylic Boronate Complexes
Yamamoto, Yoshinori,Yatagai, Hidetaka,Maruyama, Kazuhiro
, p. 1072 - 1073 (1980)
The threo-selectivity of the reaction of but-2-enyl-lithium with aldehydes in the presence of certain trialkylboranes is enhanced; the corresponding allylic boronate complexes are presumably involved as intermediates.
Reversal of Diastereoselectivity in the BF3-Promoted Addition of Halobis(cyclopentadienyl)crotyltitanium Compounds to Aldehydes
Reetz, M. T.,Sauerwald, M.
, p. 2292 - 2293 (1984)
Diastereoselectivity in the reaction of halobis(cyclopentadienyl)crotyltitanium reagents with aldehydes is reversed if BF3 is added, erythro adducts being formed preferentially.
Kinetic Resolution of α-Silyl-Substituted Allylboronate Esters via Chemo- and Stereoselective Allylboration of Aldehydes
Park, Jinyoung,Jung, Yongsuk,Kim, Jeongho,Lee, Eunsung,Lee, Sarah Yunmi,Cho, Seung Hwan
supporting information, p. 2371 - 2376 (2020/12/01)
We describe the kinetic resolution of α-silyl-substituted allylboronate esters via chiral phosphoric acid-catalyzed chemo-, diastereo- and enantioselective allylboration of aldehydes. This process provides two synthetically versatile enantioenriched compo
Catalytic Allylation of Aldehydes Using Unactivated Alkenes
Tanabe, Shun,Mitsunuma, Harunobu,Kanai, Motomu
supporting information, p. 12374 - 12381 (2020/07/14)
Simple feedstock organic molecules, especially alkenes, are attractive starting materials in organic synthesis because of their wide availability. Direct utilization of such bulk, inert organic molecules for practical and selective chemical reactions, however, remains limited. Herein, we developed a ternary hybrid catalyst system comprising a photoredox catalyst, a hydrogen-atom-transfer catalyst, and a chromium complex catalyst, enabling catalytic allylation of aldehydes with simple alkenes, including feedstock lower alkenes. The reaction proceeded under visible-light irradiation at room temperature and with high functional group tolerance. The reaction was extended to an asymmetric variant by employing a chiral chromium complex catalyst.
Photoredox Ni-Catalyzed Branch-Selective Reductive Coupling of Aldehydes with 1,3-Dienes
Chen, Jie,Gu, Zheng-Yang,Li, Wen-Duo,Li, Yan-Lin,Xia, Ji-Bao
, p. 1528 - 1534 (2020/02/04)
We report here a Ni-catalyzed reductive coupling of aldehydes with widely available 1,3-dienes under visible-light photoredox dual catalysis. The homoallyic alcohols are obtained in broad scope with complete branched regioselectivity. Hantzsch ester is used as the hydrogen radical source to oxidize low-valent nickel salt affording Ni-H species. Preliminary mechanistic studies indicate a successive single-electron transfer (SET) pathway and the generation of a key π-allylnickel intermediate via Ni-H insertion of 1,3-diene in this synergistic catalytic process.
Bi(cyclopentyl)diol-Derived Boronates in Highly Enantioselective Chiral Phosphoric Acid-Catalyzed Allylation, Propargylation, and Crotylation of Aldehydes
Yuan, Jinping,Jain, Pankaj,Antilla, Jon C.
, p. 12988 - 13003 (2020/11/23)
In this study, we disclose the catalytic addition of bi(cyclopentyl)diol-derived boronates to aldehydes promoted by chiral phosphoric acids, allowing for the formation of enantioenriched homoallylic, propargylic, and crotylic alcohols (up to >99% enantiom
Stereodivergent total synthesis of Br-nannocystins underpinning the polyketide (10R,11S) configuration as a key determinant of potency
Tian, Yunfeng,Wang, Jiyan,Liu, Wenjie,Yuan, Xiaoya,Tang, Yang,Li, Jing,Chen, Yue,Zhang, Weicheng
, p. 568 - 578 (2019/01/21)
Continuing our investigation into the structure-activity relationship of antiproliferative macrocyclic nannocystins, we describe herein total synthesis of all four stereoisomers of Br-nannocystins as well as a simplified analogue varying at the polyketide C10 and C11 positions. Biological evaluation of these compounds against PANC1 cancer cell lines showed that both the (10R,11S) configuration and its associated two substituents are crucial for high potency.
Active bismuth mediated allylation of carbonyls/N-tosyl aldimines and propargylation of aldehydes in water
Sawkmie, Micky Lanster,Paul, Dipankar,Khatua, Snehadrinarayan,Chatterjee, Paresh Nath
, (2019/06/08)
Abstract: Active bismuth is synthesized by the chemical reduction of bismuth trichloride using freshly prepared sodium stannite solution as the reducing agent at room temperature. The as-synthesized active bismuth is applied as a reagent for the synthesis of homoallyl alcohol/homopropargyl alcohol from allyl bromide/propargyl bromide and carbonyl compounds in water at 50°C. The homoallyl amines are also synthesized from N-tosyl aldimines and allyl bromide using active bismuth reagent in good yields. No assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere is required for this reaction. The waste bismuth material obtained after the completion of the organic reaction can be reduced to active bismuth by sodium stannite solution and successfully reused for mediating the allylation of aldehydes. Graphical Abstract:: Synopsis Active bismuth mediated allylation/crotylation of aldehydes is developed in water to get homoallyl alcohols. The method is also applied for the allylation of N-tosyl aldimines and propargylation of aldehydes in water to achieve the homoallyl amines and homopropargyl alcohols, respectively. The reactions do not require the assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere.[Figure not available: see fulltext.].
