Highly active and efficient catalysts for alkoxycarbonylation of alkenes

Abstract

Carbonylation reactions of alkenes constitute the most important industrial processes in homogeneous catalysis. Despite the tremendous progress in this transformation, the development of advanced catalyst systems to improve their activity and widen the range of feedstocks continues to be essential for new practical applications. Herein a palladium catalyst based on 1,2-bis((tert-butyl(pyridin-2-yl)phosphanyl)methyl)benzene L3 (pytbpx) is rationally designed and synthesized. Application of this system allows a general alkoxycarbonylation of sterically hindered and demanding olefins including all kinds of tetra-, tri- and 1,1-disubstituted alkenes as well as natural products and pharmaceuticals to the desired esters in excellent yield. Industrially relevant bulk ethylene is functionalized with high activity (TON: >1,425,000; TOF: 44,000 h−1 for initial 18 h) and selectivity (>99%). Given its generality and efficiency, we expect this catalytic system to immediately impact both the chemical industry and research laboratories by providing a practical synthetic tool for the transformation of nearly any alkene into a versatile ester product.

Synthesis of Carboxylic Acids by Palladium‐Catalyzed Hydroxycarbonylation

“…In this respect, the groups of Monflier and later on Ionescu investigated the recyclability of watersoluble Pd-catalysts. [55][56][57] Furthermore, we demonstrated the superiority of these ligands for selective formic acid decomposition reactions. [51,52] However,i nt his patent the stability of the recycled catalyst is not reported and it is only stated that the catalyst system was "almost exclusively detected in the organic phase".…”

Trimming it short: PNLDC1 is required for piRNA maturation during mouse spermatogenesis

“…However, the enzyme that is required for piRNA 3 0 end maturation in vertebrates remained enigmatic. Nishimura et al [1] in this issue of EMBO Reports and two independent studies [2,3] now identified PNLDC1 as the exonuclease that is responsible for piRNA 3 0 end processing and transposon silencing during mouse spermatogenesis. Together, these studies establish PNLDC1 as the piRNA 3 0 end trimmer in mouse.…”

Carbonylative Suzuki coupling reactions catalyzed by ONO pincer–type Pd(II) complexes using chloroform as a carbon monoxide surrogate

“…A review of the literature reveals that the direct carbonyl insertion reactions involve the use of carbon monoxide (CO) as a highly toxic gas and suffer from one or more drawbacks, such as rigorous reaction conditions, high temperature, difficulty in handling of reactants, and limited utility of high pressurized toxic CO gas, precluding their large‐scale industrial applications. To avoid these drawbacks, metal carbonyls, formic acid, acid chloride, silacarboxylic acids, dimethylformamide (DMF), COgen and SilaCOgen, etc.…”