John A Soderquist

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The simple and efficient syntheses of B-allyl-10-(phenyl)-9-borabicyclo[3.3.2]decane (1) in both enantiomeric forms are reported. The remarkable enantioselectivity (81-99% ee) of these reagents in the allylboration process at -78 degrees C is only modestly diminished when the process is conducted at 0 degrees C, a phenomenon attributable to its rigid(More)
The efficient stepwise construction of optically pure trans-4-substituted 2-boryl-1,3-butadienes 6 is described. Hydroboration of 1-alkynes with either enantiomeric form of 3 leads to the pure trans-1-alkenylboranes 4 which undergo addition of alpha-ethoxyvinyllithium followed by a BF(3)-mediated 1,2-B-->C vinylic group migration to provide 6. These(More)
The remarkable versatility and selectivity of the 10-(trimethylsilyl)-9-borabicyclo[3.3.2]decanes (10-TMS-9-BBDs) in the allyl- and crotylboration of representative aldehydes are reported. The new reagents are prepared through air-stable crystalline pseudoephedrine borinic ester complexes of the 10-TMS-9-BBDs (4), which are available in 63% overall yield(More)
Simple and efficient Grignard procedures are reported for the syntheses of B-allenyl-10-(phenyl)-9-borabicyclo[3.3.2]decane (1) and its B-(gamma-trimethylsilylpropargyl) counterpart (2) in both enantiomeric forms. Both add selectively to ketones, providing propargyl- and alpha-silylallenyl 3-degree-carbinols, respectively (i.e., 6 (61-93% ee) and 9 (64-98%(More)
The first asymmetric γ-alkoxyallylboration of representative ketones provides β-alkoxy tert-homoallylic alcohols 10 whose diastereoselectivities range from 99% syn (acetophenone) to 99% anti (pinacolone) both with high ee (>95%). This distribution is attributable to the c/t isomerization of the BBD reagents and the greater reactivity of 7 vs 1 and of(More)
Simple Grignard procedures provide methallylboranes 1a and 1b in enantiomerically pure form from air-stable precursors in 98% and 95% yields, respectively. These reagents add smoothly to aldehydes and methyl ketones, respectively, providing branched 2 degrees- (6, 69-89%, 94-99% ee) and 3 degrees- (10, 71-87%, 74-96% ee) homoallylic alcohols.
The asymmetric allylboration of N-H aldimines with optically pure trans-4-substituted-2-boryl-1,3-dienes 6 is described. These organoboranes 6 serve as near-perfect asymmetric allylborating agents for N-H aldimines for the preparation of anti-1,2-disubstituted-3,4-pentadien-1-amines 11 as essentially single diastereomers in enantiomerically pure form (>98%(More)
Representative organoborane mixtures were quantitatively converted to their borohydrides through their reaction with activated KH (KH), permitting their detailed analysis by (11)B NMR. Through the treatment of commercial KH with a THF solution of lithium aluminum hydride (LAH), a dramatic change in the surface morphology results as revealed by scanning(More)
The allylboration of enantiomerically pure N-triisopropylsilyl-alpha-amino aldehydes (2) with B-allyl-10-trimethylsilyl-9-borabicyclo[3.3.2]decanes (1) proceeds cleanly at -78 degrees C, exhibiting essentially complete reagent control. After an oxidative workup, an HOAc-mediated N-->O TIPS rearrangement facilitates the clean formation of stable O-TIPS(More)
The synthesis of mixed borabicyclodecane (BBD)-derived 1,3-diborylpropenes (trans-1) is described. These new bimetallic reagents are effective for the selective asymmetric allylboration first of ketones (or ketimines) and second of aldehydes (or aldimines). Formed as a thermodynamic mixture of trans regioisomers from cis-1 through a series of 1,3-borotropic(More)