24596-19-8Relevant articles and documents
Catalyst
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Paragraph 0426; 0463-0466, (2021/03/16)
A complex of formula (I): (I′) M is Hf; each X is a sigma ligand; L is a bridge of formula -(ER82)y—; y is 1 or 2; E is C or Si; each R8 is independently a C1-C20-hydrocarbyl, tri(C1-C20-alkyl)silyl, C6-C20- aryl, C7-C20-arylalkyl or C7-C20-alkylaryl or L is an alkylene group such as methylene or ethylene; Ar and Ar′ are each independently an aryl or heteroaryl group optionally substituted by 1 to 3 groups R1 or R1′ respectively; R1 and R1′ are each independently the same or can be different and are a linear or branched C1-C6-alkyl group, C7-20 arylalkyl, C7-20 alkylaryl group or C6-20 aryl group with the proviso that if there are four or more R1 and R1′ groups present in total, one or more of R1 and R1′ is other than tert butyl; R2 and R2′ are the same or are different and are a CH2—R9 group, with R9 being H or linear or branched C1-C6-alkyl group, C3-8 cycloalkyl group, C6-10 aryl group; each R is a —CH2—, —CHRx- or C(Rx)2-group wherein Rx is C1-4 alkyl and where m is 2-6; R5 is a linear or branched C1-C6-alkyl group, C7-20 arylalkyl, C7-20 alkylaryl group or C6-C20-aryl group; R6 is a C(R10)3 group, with R10 being a linear or branched C1-C6 alkyl group; and R6 and R7′ are the same or are different and are H or a linear or branched C1-C6-alkyl group. Invention relates also to a catalyst in solid form comprising (i) a complex of formula (I) and (ii) a cocatalyst of an aluminium compound and (iii) a cocatalyst of a boron compound.
Asymmetric acyl-Mannich reaction of isoquinolines with α-(diazomethyl)phosphonate and diazoacetate catalyzed by chiral Br?nsted acids
Wu, Wei,Wang, Yan,Guo, Jing,Cai, Liu,Chen, Yuan,Huang, Yanmin,Peng, Yungui
supporting information, p. 11235 - 11238 (2020/10/06)
An efficient asymmetric acyl-Mannich reaction of isoquinolines with α-(diazomethyl)phosphonate and diazoacetate has been developed using chiral spiro phosphoric acids as catalysts. This reaction allowed the construction of a series of chiral 1,2-dihydroisoquinolines bearing a tertiary stereocenter at the C1 position with up to 98% yield and 99% ee.
Visible-light-promoted oxidative halogenation of (hetero)arenes
Jiang, Xuefeng,Li, Yiming,Lu, Lingling
supporting information, p. 5989 - 5994 (2020/10/18)
Organic halides are critical building blocks that participate in various cross-coupling reactions. Furthermore, they widely exist as natural products and artificial molecules in drugs with important physiological activities. Although halogenation has been well studied, to the best of our knowledge, studies focussing on sensitive systems (e.g.aryl amines) have not been reported. Herein, we describe a compatible oxidative halogenation of (hetero)arenes with air as the oxidant and halide ions as halide sources under ambient conditions (visible light, air, aqueous system, room temperature, and normal pressure). Moreover, this protocol is practically feasible for gram-scale synthesis, showing potential for industrial application.
