Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• construction of axial chirality [7][8][9][10][11][12][13][14]. Axially chiral biaryl and heterobiaryl units are widely used as basic building blocks for chiral ligands [14], chiral catalysts [14][15][16][17] (Figure 1), various natural products, drugs and bioactive molecules [18][19], pharmaceutical agents [20

• ][21] (Figure 2), and chiral building blocks in modern organic synthesis [5]. During the past decades, both C2 and non-C2 symmetric axially chiral biaryl compounds such as BINAP, BINAM, NOBIN and their derivatives BINOL have played a crucial role as ligands in the development of transition-metal

• corresponding axially chiral biaryl diols 8 were prepared in good yields (60–90%) and excellent enantioselectivities (90–99% ee) in the presence of CPA 2 (Scheme 3). The stereoselectivity of the reaction is only moderately affected by the position and electronic properties of the substituents on the aromatic

Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

• Yongsu Li,
• Bendu Pan,
• Xuefeng He,
• Wang Xia,
• Yaqi Zhang,
• Hao Liang,
• Chitreddy V. Subba Reddy,
• Rihui Cao and
• Liqin Qiu

Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85

• Abstract Pd-catalyzed asymmetric Suzuki–Miyaura couplings of 3-methyl-2-bromophenylamides, 3-methyl-2-bromo-1-nitrobenzene and 1-naphthaleneboronic acids have been successfully developed and the corresponding axially chiral biaryl compounds were obtained in very high yields (up to 99%) with good

• ], especially on how to obtain the large steric axially chiral biaryl with a high yield and good enantioselectivity through those coupling strategies [13]. Therefore, based on our previous research [60][61][62][63][64][65], we herein present a new method through which those large steric axially chiral biaryl

• structure (Scheme 4). Conclusion In summary, a Pd-catalyzed asymmetric Suzuki–Miyaura coupling of 3-methyl-2-bromophenylamides or 3-methyl-2-bromo-1-nitrobenzene and 1-naphthaleneboronic acids has been successfully developed and the corresponding axially chiral biaryl compounds were obtained in very high

A survey of chiral hypervalent iodine reagents in asymmetric synthesis

• Soumen Ghosh,
• Suman Pradhan and
• Indranil Chatterjee

Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107

• purpose various chiral iodine reagents were synthesized having an axially chiral biaryl backbone. In this part, we mainly focused on the transformations using chiral iodine reagents instead of achiral iodine reagents in a combination with other chiral sources [61]. More than one century after Pribam

• for the alkynylation of β-ketoesters [76]. Pouységu and Quideau et al. prepared new axially chiral biaryl I(III) reagents 18 assembled with alkynyl ligands. They were able to achieve alkynylation of β-ketoesters 114 as well as dearomative alkynylation of phenolic derivatives 118 to obtain derivatives

Stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)”s: functionalization, rotational barriers and non-covalent interactions

• Golo Storch,
• Sebastian Pallmann,
• Frank Rominger and
• Oliver Trapp

Beilstein J. Org. Chem. 2016, 12, 1453–1458, doi:10.3762/bjoc.12.141

• Axially chiral biaryl compounds such as BINAP (2,2’-bis(diphenylphosphino)-1,1’-binaphthyl) represent widely used and highly efficient ligands that can be applied in a variety of enantioselective catalytic transformations. Unlike BINAP, the related stereodynamic BIPHEP (2,2’-bis(diphenylphosphino)-1,1

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• group not only achieved the directing role but also acts as an important component unit of the C–H functionalized products. In this paper, we use the axially chiral biaryl phosphine oxides as substrates and report the synthesis of various chiral phosphorus ligands with high enantiomeric selectivity

• system of P(O)R2-directed Pd-catalyzed C–H activation. These compounds could be transformed to trivalent phosphorus compounds by silane to obtain the corresponding phosphorous ligands. Conclusion In summary, a series of substrates with axially chiral biaryl compounds containing a P(O)Ar2 directing group

Cationic gold(I) axially chiral biaryl bisphosphine complex-catalyzed atropselective synthesis of heterobiaryls

• Tetsuro Shibuya,
• Kyosuke Nakamura and
• Ken Tanaka

Beilstein J. Org. Chem. 2011, 7, 944–950, doi:10.3762/bjoc.7.105

• from N-alkenyl-arylethynylamides was thus investigated. Although cationic gold(I)/axially chiral biaryl bisphosphine complexes [19][20][21][22][23][24][25][26][27][28][29][30][31] have been frequently employed in asymmetric variants of cationic gold(I) catalyses [32][33][34][35][36][37][38], including

• 6-endo-dig and 6-exo-dig cyclizations [39][40][41], the use of these gold(I) complexes gave almost racemic products [42]. Fortunately, cationic palladium(II)/axially chiral biaryl bisphosphine complexes were found to be effective catalysts, and a cationic palladium(II)/(S)-xyl-Segphos complex showed

• the highest enantioselectivity (Scheme 2) [42]. In addition, the cationic palladium(II)/axially chiral biaryl bisphosphine complexes were able to catalyze the asymmetric intramolecular hydroarylation of N-aryl-arylethynylamides leading to axially chiral 4-aryl-2-quinolinones, and the cationic

Synthesis of chiral mono(N-heterocyclic carbene) palladium and gold complexes with a 1,1'-biphenyl scaffold and their applications in catalysis

• Lian-jun Liu,
• Feijun Wang,
• Wenfeng Wang,
• Mei-xin Zhao and
• Min Shi

Beilstein J. Org. Chem. 2011, 7, 555–564, doi:10.3762/bjoc.7.64

• catalysts in chiral induction reactions [19][20][21][22][23][24][25]. The axially chiral biaryl framework, widely used in the design of chiral ligands such as BINAP [26][27], BINOL [28][29], and boxax [30], has proved to be very rigid, and was introduced in the development of NHC ligands by the Hoveyda

• with sterically hindered N-substituents. NHCs with axially chiral biaryl frameworks. ORTEP drawing of NHC–Pd(II) complex (S)-7a with thermal ellipsoids at the 30% probability level. Selected bond distances (Å) and angles (deg): Pd–C1 = 2.050(5), Pd–C25 = 2.154(7), Pd–C26 = 2.128(9), Pd–C27 = 2.168(8

Ring strain and total syntheses of modified macrocycles of the isoplagiochin type

• Andreas Speicher,
• Timo Backes,
• Kerstin Hesidens and
• Jürgen Kolz

Beilstein J. Org. Chem. 2009, 5, No. 71, doi:10.3762/bjoc.5.71

• macrocycles. Keywords: axially chiral biaryl; isoplagiochin; macrocycle; ring strain; total synthesis; Introduction The cyclic bisbibenzyls isoplagiochin C (1) and D (2) were isolated from the liverworts Plagiochila fruticosa [1], Plagiochila deflexa [2], Herbertus sakuraii [3] and Lepidozia fauriana [4