Acid-catalysed intramolecular addition of ß-ketoesters to 1,3-dienes.

1,3-Dienyl ß-keto esters are cyclised into bicyclolactones using the Bi(OTf)3/TfOH catalytic system. This reaction represents a rare case of simultaneous C-C and C-O bond formation at positions 1 and 3 of a 1,3-diene. Application to the synthesis of ramulosin is presented.

First-Row Late Transition Metals for Catalytic Alkene Hydrofunctionalisation: Recent Advances in C-N, C-O and C-P Bond Formation.

This review provides an outline of the most noteworthy achievements in the area of C-N, C-O and C-P bond formation by hydroamination, hydroalkoxylation, hydrophosphination, hydrophosphonylation or hydrophosphinylation reaction on unactivated alkenes (including 1,2- and 1,3-dienes) promoted by first-row late transition metal catalytic systems based on manganese, iron, cobalt, nickel, copper and zinc. The relevant literature from 2009 until mid-2017 has been covered.

Ca(II) -catalyzed alkenylation of alcohols with vinylboronic acids.

Direct alkenylation of a variety of alcohols with vinylboronic acids has been accomplished using the air-stable calcium(II) complex Ca(NTf2 )2 under mild conditions with short reaction times. For reluctant transformations, an ammonium salt was used as an additive to circumvent the reactivity issue.

Silver-free two-component approach in gold catalysis: activation of [LAuCl] complexes with derivatives of copper, zinc, indium, bismuth, and other Lewis acids.

Complexes of type [LAuCl] (L = phosphine, phosphite, NHC and others) are widely employed in homogeneous catalysis, however, they are usually inactive as such and must be used jointly with a halide scavenger. To date, this role has mostly been entrusted to silver salts (AgSbF6 , AgPF6, AgBF4, AgOTf, etc.). However, silver salts can be the source of deactivation processes or side reactions, so it is sometimes advisable to use silver-free cationic gold complexes, which can be difficult to synthesize and to handle compared with the more robust chloride. We show in this study that various Lewis acids of the transition and main group metal families are expedient substitutes to silver salts. We have tested Cu(I), Cu(II), Zn(II), In(III), Si(IV), Bi(III), and other salts in a variety of typical Au(I)-catalyzed transformations, and the results have revealed that [LAuCl] can form active species in their presence.

Synthesis of rare earth catalysts and their applications for enantioselective synthesis of heterocyclic ß-amino alcohols.

A new family of chiral lanthanide complexes derived from (R)-binaphthol has been synthesized by a one-pot procedure using only commercially available substrates. These complexes were evaluated for the aminolysis of meso-epoxides and proved to be efficient enantioselective catalysts. The samarium complex coordinated by two (R)-binaphthoxide ligands was the most enantioselective catalyst of this series. ß-Amino alcohols including heterocycles have been isolated with enantiomeric excesses up to 84%.

Recent developments in alkene hydro-functionalisation promoted by homogeneous catalysts based on earth abundant elements: formation of C-N, C-O and C-P bond.

This Perspective article provides an overview of the recent advancements in the field of intra- and inter-molecular C-N, C-O and C-P bond formation by hydroamination, hydroalkoxylation, hydrophosphination, hydrophosphonylation or hydrophosphinylation of unactivated alkenes, including allenes, 1,3-dienes and strained alkenes, promoted by (chiral) homogeneous catalysts based on earth abundant elements of the s and p blocks, the first row transition metals and the rare-earth metals. The relevant literature from 2009 until late 2014 has been covered.

Approach toward the total synthesis of griseoviridin: formation of thioethynyl and thiovinyl ether-containing nine-membered lactones through a thioalkynylation-macrolactonization-hydrostannylation sequence.

Synthesis of the lactone core 17 of 8-epi-griseoviridin is reported. Thioethynyl derivative 11 was easily prepared via an anionic coupling reaction between acetylenic compound 9 and sulfone 10. After desilylation of 11, saponification of the resulting hydroxy ester 12 followed by a Mitsunobu macrolactonization furnished the unusual triple-bond-containing nine-membered lactone 13 in 50% yield for the last two steps (39% after recrystallization). Stannylation under Magriotis conditions led to the pure regio- and stereocontrolled vinyltin 14 (80% yield). After a Sn/I exchange, palladium-catalyzed carbonylation delivered either the ester lactone 16 in 67% yield or the propargyl amide 17 in 65% yield. Synthesis of propargyl amide 17 of the lactone core of 8-epi-griseoviridin was achieved in 11.9% overall yield from commercial L-cystin dimethyl ester (nine steps).