Cobalt‐Catalyzed Addition Reaction of Organoboronic Acids with Aldehydes: Highly Enantioselective Synthesis of Diarylmethanols

Abstract

Objective To determine the best screening tests for discriminating early indicators of cardiac hypoplasia in congenital heart disease (CHD) from normal variations in fetal cardiac growth. Methods We retrospectively examined fetal echocardiograms from 90 infants with confirmed CHD: Group 1 (n = 35) with right‐sided obstructive lesions and Group 2 (n = 55) with left‐sided obstructive lesions. Our control group comprised 2735 normal fetuses, from which we determined fetal cardiac Z‐scores of right ventricle (RV), left ventricle (LV), aorta (Ao) and pulmonary artery (PA) diameters and ratios of right to left ventricle (RV:LV) and pulmonary artery to aorta (PA:Ao) size. We compared our control group to Groups 1 and 2 using ANOVA and area under receiver–operating characteristics curve (AUC) analysis. Results For Group 1, RV:LV ratio, RV‐Z‐score and PA:Ao ratio were the best screening tests, with highest AUCs (0.879, 0.868 and 0.832, respectively). For Group 2, the Ao‐Z‐score, PA:Ao and RV:LV ratios were the best screening tests, with AUCs of 0.770, 0.723 and 0.716, respectively. Conclusion None of the screening tests was found to be a perfect early discriminator for the cardiac lesions tested. Although ratios of PA:Ao and RV:LV are useful, they should be combined with fetal cardiac Z‐scores to maximize screening sensitivity. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.

Palladium-catalyzed arylation of aldehydes with bromo-substituted 1,3-diaryl-imidazoline carbene ligand

“…2 So far, these alcohols were synthesized through the nucleophilic addition using aryllithium or magnesium reagents. 3 Recent development in the catalytic 1,2-addition of arylboron compounds to carbonyl compounds with the transition metals such as Rh, 4,5 Pd, 6 Ni, 7 Ru, 8 Pt, 9 Co, 10 Cu 11 or Fe 12 has made possible the preparation of these alcohols with wide range of functional groups. Therefore, this catalytic 1,2-addition is one of the most useful methods for the preparation of various substituted benzylic alcohols, which are difficult to synthesize from the classical nucleophilic addition.…”

Grignard Reactions in Cyclopentyl Methyl Ether

“…(4-Methoxyphenyl)(phenyl)methanol (4 c). [29,30] (3-Chlorophenyl)(phenyl)methanol (4 j). [32] This compound was obtained from 1-bromo-3-chlorobenzene (1j)i n9 4% yield.…”

Regio‐ and Enantioselective Cobalt‐Catalyzed Reductive [3+2] Cycloaddition Reaction of Alkynes with Cyclic Enones: A Route to Bicyclic Tertiary Alcohols

“…[11] Herein, we report a novel cobalt-catalyzed reductive [3+2] cycloaddition of cyclic enones and alkynes affording bicyclic tertiary alcohols [12] in good to high regioselectivity. Moreover, the asymmetric version [13] of this catalytic reaction leading to two stereogenic centers can also be achieved by the proper choice of a chiral ligand (Scheme 1). This catalytic reaction provides an atom-economic method [14] for the synthesis of sterically crowded bicyclic tertiary alcohols, an important motif present in Galbulimima alkaloids, [15] under mild conditions using relatively inexpensive cobalt metal complexes as catalysts.…”