210752-49-1Relevant academic research and scientific papers
A new stereospecific synthesis of unusual (Z)-β-branched Baylis- Hillman adducts
Li, Guigen,Wei, Han-Xun,Willis, Steven
, p. 4607 - 4610 (1998)
A new method has been developed for the stereospecific synthesis of unusual (Z)-β-branched Baylis-Hillman adducts with high Z/E selectivity (>99 %) in modest to good yields. The process involves successful formation of anionic β-substituted [α-(alkoxycarb
Novel cross-coupling reactions between organotellurides and Grignard reagents employing a MnCl2/CuI catalytic system
Silva, Marcio S.,Ferrarini, Renan S.,Sousa, Bruno A.,Toledo, Fabiano T.,Comasseto, Jo?o V.,Gariani, Rogério A.
supporting information; experimental part, p. 3556 - 3559 (2012/09/08)
We present a general protocol for the cross-coupling reaction of Grignard reagents and organic tellurides. Aryl Grignard reagents react stereospecifically with vinyl tellurides in the presence of a catalytic amount of manganese (II) chloride and copper (I) iodide to produce good yields of the corresponding cross-coupling products.
Synthesis of β-and β,β-substituted Morita-Baylis-Hillman adducts using a two-step protocol
MaGee, David I.,Ratshonka, Same,McConaghy, Jessica,Hood, Maggie
experimental part, p. 450 - 463 (2012/06/16)
The synthesis of a large number of β-and β,β-substituted keto esters was successful by the use of the Knoevenagel condensation reaction. The stereoselectivity of these reactions was improved by alteration of various substituent groups. Although there were
An ester enolate-Claisen rearrangement route to substituted 4-alkylideneprolines. Studies toward a definitive structural revision of lucentamycin A
Ranatunga, Sujeewa,Kim, Jinsoo S.,Pal, Ujjwal,Del Valle, Juan R.
experimental part, p. 8962 - 8976 (2011/12/03)
Substituted 4-alkylideneprolines represent a rare class of naturally occurring amino acids with promising biological activities. Lucentamycin A is a cytotoxic, marine-derived tripeptide that harbors a 4-ethylidine-3-methylproline (Emp) residue unique among known peptide natural products. In this paper, we examine the synthesis of Emp and related 4-alkylideneprolines employing a versatile ester enolate-Claisen rearrangement. The scope and selectivity of the key rearrangement reaction are described with a number of diversely substituted glycine ester substrates. Treatment of the allyl esters with excess NaHMDS at ambient temperature gives rise to highly substituted α-allylglycine products with good to excellent diastereoselectivities. Resolution of dipeptide diastereomers and cyclization to form the pyrrolidine rings provide rapid access to stereopure prolyl dipeptides. We have applied this strategy to the synthesis of four Emp-containing isomers of lucentamycin A in pursuit of a definitive stereochemical revision of the natural product. Our studies indicate that the Emp stereogenic centers are not the source of structural misassignment. The current strategy should find broad utility in the synthesis of additional natural product analogues and related 3-alkyl-4-alkylidene prolines.
The first successful intermolecular Heck reaction of Baylis-Hillman adducts: synthesis of β-aryl substituted Baylis-Hillman adducts
Kim, Jeong Mi,Kim, Ko Hoon,Kim, Taek Hyeon,Kim, Jae Nyoung
, p. 3248 - 3251 (2008/09/21)
The first successful intermolecular Heck reaction between Baylis-Hillman adducts and aryl iodides was achieved under the conditions comprising Pd(OAc)2/n-Bu4NBr/KOAc in CH3CN.
Vicinal functionalization of propiolate esters via a tandem catalytic carbocupriation-Mukaiyama aldol reaction sequence
Mueller, Amanda J.,Jennings, Michael P.
supporting information; experimental part, p. 1649 - 1652 (2009/04/07)
The vicinal functionalization of propiolate esters via a tandem catalytic carbocupration-Mukaiyama aldol reaction sequence has been investigated. It has been shown that catalyst loadings as low as 8 mol % readily allow for good yields and excellent diastereoselectivities (>20:1) for a series of Grignard reagents and aldehydes.
A highly stereoselective TMSOTf-mediated catalytic carbocupration of alkynoates
Mueller, Amanda J.,Jennings, Michael P.
, p. 5327 - 5329 (2008/09/17)
(Chemical Equation Presented) The TMSOTf-mediated catalytic carbocupration of ynoates has been investigated. It has been shown that catalyst loadings as low as 5 mol % readily allow for high yields and diastereosetectivities for a series of aromatic Grignard reagents. In addition, we have been successful in vicinally functionalizing 1a via initial TMSOTf-mediated catalytic carbocupration followed by a secondary electrophilic capture of the TMS allenoate intermediate.
Vinylalumination for the Synthesis of Functionalized Allyl Alcohols, Vinylepoxides, and α-Alkylidene-β-hydroxy-γ-lactones
Ramachandran, P. Veeraraghavan,Rudd, Michael T.,Burghardt, Thomas E.,Ram Reddy, M. Venkat
, p. 9310 - 9316 (2007/10/03)
A modified hydroalumination protocol for the preparation of [α-(ethoxycarbonyl)vinyl]diisobutylaluminum and its β-methyl or -phenyl analogues was developed. These vinylaluminum reagents react with aldehydes and ketones to provide the corresponding functio
An improved vinylalumination procedure replacing HMPA with NMO for the hydroalumination of α-acetylenic esters and ketones
Ramachandran, P. Veeraraghavan,Reddy, M. Venkat Ram,Rudd, Michael T.
, p. 1979 - 1980 (2007/10/03)
Replacing carcinogenic HMPA with NMO, a higher yielding, enviornmentally benign procedure for the vinylalumination of carbonyl compounds with [α-(ethoxycarbonyl)vinyl]diisobutylaluminium and its β-methyl or -phenyl analogs, as well as [α-(acetyl)vinyl]dii
