86474-76-2Relevant academic research and scientific papers
Highly (≥98a%) selective trisubstituted alkene synthesis of wide applicability via fluoride-promoted Pd-catalyzed cross-coupling of alkenylboranes
Negishi, Ei-Ichi,Tobrman, Tomas,Rao, Honghua,Xu, Shiqing,Lee, Ching-Tien
, p. 696 - 701 (2010)
(Z)-β-bromo-1-propenyl(pinacol)borane (4), recently made available in 85a% yield as a ≥98a% isomerically pure compound via bromoboration of 1-propyne, has been converted to β-alkyl-, aryl-, and alkenyl-substituted (Z)-2-methyl-1-alkenyl(pinacol)boranes (2
Catalytic wittig reactions of semi- and nonstabilized ylides enabled by ylide tuning
Coyle, Emma E.,Doonan, Bryan J.,Holohan, Andrew J.,Walsh, Killian A.,Lavigne, Florie,Krenske, Elizabeth H.,O'Brien, Christopher J.
supporting information, p. 12907 - 12911 (2016/02/18)
The first examples of catalytic Wittig reactions with semistabilized and nonstabilized ylides are reported. These reactions were enabled by utilization of a masked base, sodium tert-butyl carbonate, and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the phosphorus center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity up to >95:5, E/Z. Time for a tune up: Catalytic Wittig reactions with semi- and nonstabilized ylides were enabled by use of a masked base (NaOCO2tBu) and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the P center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity.
METHODS FOR PHOSPHINE OXIDE REDUCTION IN CATALYTIC WITTIG REACTIONS
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Page/Page column 58; 59; 64, (2014/09/29)
A method for increasing the rate of phosphine oxide reduction, preferably during a Wittig reaction comprising use of an acid additive is provided. A room temperature catalytic Wittig reaction (CWR) the rate of reduction of the phosphine oxide is increased due to the addition of the acid additive is described. Furthermore, the extension of the CWR to semi-stabilized and non-stabilized ylides has been accomplished by utilization of a masked base and/or ylide-tuning.
On the scope of the Pt-catalyzed Srebnik diborylation of diazoalkanes. An efficient approach to chiral tertiary boronic esters and alcohols via B-stabilized carbanions
Wommack, Andrew J.,Kingsbury, Jason S.
, p. 3163 - 3166 (2014/05/20)
Conditions milder than those previously reported are shown to be generally applicable to the Pt-catalyzed insertion of non-carbonyl-stabilized diazoalkanes into B2pin2. Selective transformation of one (pinacolato)boryl unit in the products is enabled by rapid, low-temperature deboronation in the presence of a Lewis base and genesis of a highly reactive B-stabilized carbanion.
Alkenylation of thiophenes and furans at the 2-position and a synthesis of allenes conjugated with α,β-unsaturated ester with magnesium alkylidene carbenoids
Mori, Natsuki,Obuchi, Kazumi,Katae, Takashi,Sakurada, Jo,Satoh, Tsuyoshi
experimental part, p. 3509 - 3517 (2009/08/15)
The reaction of 1-chlorovinyl p-tolyl sulfoxides, derived from ketones and chloromethyl p-tolyl sulfoxide, with i-PrMgCl at -78 °C gave magnesium alkylidene carbenoids. Treatment of the magnesium carbenoids with 2-lithiothiophenes and 2-lithiofurans resul
Alkenylation of thiophenes at the 2-position with magnesium alkylidene carbenoids
Satoh, Tsuyoshi,Mori, Natsuki,Obuchi, Kazumi
, p. 6453 - 6457 (2008/02/12)
Treatment of magnesium alkylidene carbenoids, generated from 1-chlorovinyl p-tolyl sulfoxides with isopropylmagnesium chloride at -78 °C in toluene, with 2-lithiothiophenes gave 2-alkenylated thiophenes in good to high yields. The intermediate of this rea
Synthesis of All of the Monomethyl Isomers of Naphthothiophene
Tominaga, Yoshinori,Tedjamulia, Marvin L.,Castle, Raymond N.,Lee, Milton L.
, p. 487 - 490 (2007/10/02)
All isomers of the monomethylnaphthothiophenes were synthesized by photocyclization of 2-styrylthiophenes which were either prepared by the Wadsworth-Emmons reaction or by the condensation of 2-lithiothiophene with the corresponding carbonyl compou
