We report a Pd-catalyzed intermolecular hydrophosphinylation of 1,3-dienes to afford chiral allylic phosphine oxides. Commodity dienes and air stable oxides couple generate organophosphorus building blocks with high enantio- regiocontrol. This method constitutes the first asymmetric dienes.

In this Article, we expand upon the catalytic hydrothiolation of 1,3-dienes to afford either allylic or homoallylic sulfides with high regiocontrol. Mechanistic studies support a pathway in which regioselectivity is dictated by choice counterion associated Rh center. Non-coordinating counterions, such as SbF6–, allow for η4-diene coordination complexes and result sulfides. contrast, coordinating Cl–, favor neutral diene binds η2 We propose mechanisms that rationalize fractional dependence on...

In this article, we advance Rh-catalyzed hydrothiolation through the divergent reactivity of cyclopropenes. Cyclopropenes undergo to provide cyclopropyl sulfides or allylic sulfides. The choice bisphosphine ligand dictates whether pathway involves ring-retention ring-opening. Mechanistic studies reveal origin for switchable selectivity. Our results suggest two pathways share a common cyclopropyl-Rh(III) intermediate. Electron-rich Josiphos ligands promote direct reductive elimination from...

We describe a copper catalyst that promotes the addition of phosphines to cyclopropenes at ambient temperature. A range cyclopropylphosphines bearing different steric and electronic properties can now be accessed in high yields enantioselectivities. Enrichment phosphorus stereocenters is also demonstrated via Dynamic Kinetic Asymmetric Transformation (DyKAT) process. combined experimental theoretical mechanistic study supports an elementary step featuring insertion Cu

Highly enantioselective synthesis of nitrocyclopropanes was achieved via the organocatalytic conjugate addition dimethyl bromomalonate to nitroalkenes and consequent intramolecular cyclopropanation. 6′-Demethyl quinine found be efficient catalyst. Excellent enantioselectivities, diastereoselectivities, good yields were obtained for a variety aryl or heteroaryl nitroethylenes.

A new synthesis of indole derivatives has been achieved through intramolecular dehydrative coupling tertiary amines and ketones promoted by KO-t-Bu/DMF. The reaction probably proceeds via an α-amino alkyl radical pathway.

This study showcases the first enantioselective hydroselenation of styrenes. Organoselenium building blocks are accessed with selectivity for branched isomer. Through a Rh-hydride pathway, C–Se bonds can be forged excellent regio- and enantiocontrol.

A novel metal-free one-pot protocol for the effective and efficient synthesis of 3-phosphinoylbenzofurans via a phospha-Michael addition/cyclization H-phosphine oxides in situ generated ortho-quinone methides is described. Based on expeditious construction C(sp2)–P bonds, asymmetric optically pure containing chiral P-stereogenic center has also been probed by using RP-(−)-menthyl phenylphosphine oxide.

Organocatalytic asymmetric conjugate addition of α-nitroketones to β,γ-unsaturated α-keto esters has been developed. A pyrrolidine-based thiourea-tertiary amine was identified as the best catalyst. The reaction found proceed via cascade and acyl transfer reaction. number were examined in this transformation. 5-Nitro-2-acyloxypent-2-enoates obtained good yields (up 99%) enantioselectivities 99% ee). products could be hydrolyzed provide 5-nitro-2-oxopentanoates, which are not available from...

Abstract The efficient construction of CN double bonds has been achieved by the Ir‐catalyzed intramolecular acceptorless dehydrogenative cross‐coupling tertiary amines and amides. An iridium/2‐hydroxypyridine complex was identified as highly catalyst. A number quinazolinone derivatives prepared in excellent yields. iridium‐mediated CH activation mechanism is proposed. This finding provides an unprecedented strategy for direct imidation sp 3 bonds. magnified image

Functionalized P,C-stereogenic tertiary phosphine oxides were prepared by the addition of (RP)-menthyl phenylphosphine oxide to activated olefins, in high drP and drC, isolated excellent yields. The reaction was readily catalyzed Ca(OH)2 or occurred with gentle heating. A wide range substrates, including vinyl ketones, esters, nitriles, nitro alkenes, can be used reaction.

Unprecedented constructions of C═C double bonds have been achieved by Ir-catalyzed intramolecular dehydrogenative and dehydrative cross-coupling tertiary amines ketones. The reactions are proposed to proceed via an Ir-mediated C–H activation mechanism.

P,C-Stereogenic 1,3-bisphosphinylpropanes 3 that have up to five stereogenic centers could be obtained stereoselectively in high yields by a one-step reaction of (RP)-menthylphenylphosphine oxide 1 with α,β-unsaturated aldehydes 2 catalyzed KOH at room temperature. A mechanism was proposed as involve stereoselective intermolecular 1,3′-phosphorus migration from the 1,2-adduct another generating 1,4-adduct subsequently reacts produce 3.

A diastereomeric mixture of secondary phosphine oxide is stereospecifically converted to chlorophosphine salt by treatment with oxalyl chloride, which stereoselectively affords P-inverted or retained tertiary phosphines, depending on the substitution aliphatic aromatic Grignard reagents, respectively, in high 99% yield and 99:1 dr. The repulsion π-electron aryl lone electron pair phosphorus proposed for P-retained substitution.

The secondary RP-(-)-menthyl alkylphosphine oxide was confirmed as configurationally stable toward base and used in base-promoted alkylation, stereospecifically affording P-retained bis or functional tertiary phosphine oxides excellent yields. alkylated products were deoxygenated using oxalyl chloride followed by ZnCl2-NaBH4 to form P-inversed bidentate boranes high stereoselectivities.

The conjugate addition of cyclic 1,3-dicarbonyl compounds to β,γ-unsaturated α-keto-esters was studied using a series chiral bifunctional organocatalysts.Takemoto's catalyst found be most efficient for this transformation.Excellent yields and good enantioselectivities were achieved variety compounds.A catalytic mechanism is proposed.The method provides new asymmetric synthetic route courmarin derivatives.

Lewis base-catalyzed cascade nucleophilic/aza-Michael addition reaction of N-alkoxy β-oxo-acrylamides with isocyanates has been developed to afford various highly functionalized hydantoin derivatives in 80-98% yields under mild conditions. The intriguing features this method include metal-free conditions, low catalyst loading, broad substrate scope and short time.

We report a light-promoted hydroselenation of alkenes with high

P,C-Stereogenic α-amino phosphine oxides were prepared from the addition of (RP )-menthyl phenyl oxide to chiral aldimines under neat condition at 80 °C in up 91:9 drC and 99% yields. The diastereoselectivity was mainly induced by phosphorus that showed matched or mismatched induction with (S)- (R)-aldimines, respectively.

We report a light-promoted hydroselenation of alkenes with high anti-Markovnikov selectivity. Spectroscopic, kinetic, and computational mechanistic studies indicate that blue light activates an aryl diselenide to generate seleno radical; this radical adds into alkene form β-seleno carbon radical. Subsequent hydrogen atom transfer (HAT) generates the linear selenide selectivity in preference branched isomer. These reveal unique β-selenium effect, where β imparts anti-selectivity for addition...