Identification of KU-55933 as an anti-atherosclerosis compound by using a hemodynamic-based high-throughput drug screening platform.

Several compounds have been used for atherosclerosis treatment, including clinical trials; however, no anti-atherosclerotic drugs based on hemodynamic force-mediated atherogenesis have been discovered. Our previous studies demonstrated that "small mothers against decapentaplegic homolog 1/5" (Smad1/5) is a convergent signaling molecule for chemical [e.g., bone morphogenetic proteins (BMPs)] and mechanical (e.g., disturbed flow) stimulations and hence may serve as a promising hemodynamic-based target for anti-atherosclerosis drug development. The goal of this study was to develop a high-throughput screening (HTS) platform to identify potential compounds that can inhibit disturbed flow- and BMP-induced Smad1/5 activation and atherosclerosis. Through HTS using a Smad1/5 downstream target inhibitor of DNA binding 1 (Id-1) as a luciferase reporter, we demonstrated that KU-55933 and Apicidin suppressed Id-1 expression in AD-293 cells. KU-55933 (10 µM), Apicidin (10 µM), and the combination of half doses of each [1/2(K + A)] inhibited disturbed flow- and BMP4-induced Smad1/5 activation in human vascular endothelial cells (ECs). KU-55933, Apicidin, and 1/2(K + A) treatments caused 50.6%, 47.4%, and 73.3% inhibitions of EC proliferation induced by disturbed flow, respectively, whereas EC inflammation was only suppressed by KU-55933 and 1/2(K + A), but not Apicidin alone. Administrations of KU-55933 and 1/2(K + A) to apolipoprotein E-deficient mice inhibited Smad1/5 activation in ECs in athero-susceptible regions, thereby suppressing endothelial proliferation and inflammation, with the attenuation of atherosclerotic lesions in these mice. A unique drug screening platform has been developed to demonstrate that KU-55933 and its combination with Apicidin are promising therapeutic compounds for atherosclerosis based on hemodynamic considerations.

Reciprocal-Activation Strategy for Allylic Sulfination with Unactivated Allylic Alcohols.

A reciprocal-activation strategy for allylic sulfination with unactivated allylic alcohols was developed. In this reaction, the hydrogen bond interaction between allylic alcohols and sulfinic acids allowed for reciprocal activation, which enabled a dehydrative cross-coupling process to occur under mild reaction conditions. This reaction worked in an environmentally friendly manner, yielding water as the only byproduct. A variety of allylic sulfones could be obtained in good to excellent yields with wide functional group tolerance. In gram scale reactions, allylic sulfones could be conveniently isolated in high yield by filtration.

Dehydrative Cross-Coupling of Allylic Alcohols with Alkynes.

A highly efficient Pd/Ca catalytic system for the directly dehydrative cross-coupling of allylic alcohols with terminal alkynes was developed. This calcium salt cocatalyst facilitates the oxidative addition of the palladium catalyst (1 mol %) to the C-OH bond. Then, the in situ-generated hydroxide ion deprotonates the terminal alkynes to promote the formation of the allylalkynylpalladium intermediate, liberating water as the only byproduct. This proposed mechanism is also supported by density functional theory calculations. An anticancer agent was prepared from inexpensive starting materials on a 10 g scale.

A Ba/Pd Catalytic System Enables Dehydrative Cross-Coupling and Excellent E-Selective Wittig Reactions.

A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent E selectivity.

Allylic Phosphorus Ylides Directly Generated from Alcohols with Water as the Only Byproduct.

A novel strategy for the preparation of allylic phosphorus ylides directly from Morita-Baylis-Hillman (MBH) alcohols in an environmentally benign manner was developed. With the assistance of a calcium catalyst, the SN2' process between phosphines and allylic alcohols occurred smoothly, delivering allylic phosphorus salts and calcium-stabilized hydroxide ions. Then, in situ deprotonation gave the allylic phosphorus ylides with water as the only byproduct. Functionalized 1,3-diene moieties can be conveniently obtained by trapping the ylides through a Wittig olefination.

Bronsted Acid/Organic Photoredox Cooperative Catalysis: Easy Access to Tri- and Tetrasubstituted Alkenylphosphorus Compounds from Alcohols and P-H Species.

A Bronsted acid/organic photoredox cooperative catalytic system toward P-C bond formation from alcohols and P-H species is developed. With the assistance of visible light and TBHP, the reactions proceeded smoothly in an environmentally benign manner to give various alkenylphosphorus compounds in high efficiency.

Barium-catalyzed C-OH/P-H dehydrative cross-coupling for C-P bond construction.

A barium-catalyzed C-OH/P-H dehydrative cross-coupling protocol for the construction of C-P bonds was developed. This reaction was performed in an environmentally benign manner with water as the only by-product. A variety of allylic phosphorus compounds can be isolated in good to excellent yields.

Direct Substitution of Secondary and Tertiary Alcohols To Generate Sulfones under Catalyst- and Additive-Free Conditions.

An environmentally benign protocol that affords propargylic sulfones containing highly congested carbon centers from easily accessible alcohols and sulfinic acids with water as the only byproduct is reported. The reaction proceeded via an in situ dehydrative cross-coupling process by taking advantage of the synergetic actions of multiple hydrogen bonds rather than relying on an external catalyst and/or additives to achieve high product distribution.

Water-promoted C-S bond formation reactions.

Allylic sulfones, owning to their widespread distributions in biologically active molecules, received increasing attention in the past few years. However, the synthetic method under mild conditions is still a challenging task. In this paper, we report a sulfinic acids ligation with allylic alcohols via metal-free dehydrative cross-coupling. Both aliphatic and aromatic sulfinic acids react with various allylic alcohols to deliver the desired allylic sulfones in high yields with excellent selectivity. This carbon-sulfur bond formation reaction is highly efficient and practical since it works under metal-free, neutral, aqueous media and at room temperature in which the products even can be obtained by simple filtration without the need for organic extraction or column chromatography. Water is found to be essential for the success of this carbon-sulfur bond formation reaction. DFT calculations imply that water acts as promoter in this transformation via intermolecular hydrogen bonds.